All that means is that she wasn't being monitored as a potential host at that time, or if she was it wasn't the right type of trigger for the shard that was watching her. Taylor probably wouldn't have gotten powers in Emma's place, either because it wouldn't fit any of QA's preferred triggers or because QA was still monitoring Danny at that point.
It wasn't just the ABB atk in canon Emma didn't trigger from though she didn't trigger from anything that happened in canon. In total that would be: I think she was present for the undersider's atk on the gallery, concussed Taylor smacking her and the meeting where Taylor made the bullying claims, Levi atk; Taylor brushing her off at Arcadia which made Emma snap and atk her which led to her actually getting punished for it and the entry of Taylor's name in the system tripped the flag so the prt came rushing in quickly enough Taylor couldn't get out of the building before they arrived and then unmasked her which broke Emma enough she became a shut in that wouldn't leave her room even when Scion atked and destroyed the Bay killing her.
All that makes it pretty much certain in canon she didn't have a shard connected to her or if she did one that doesn't respond to things like what she's currently experiencing. Bcf hasn't really changed or introduced enough to have Sophia's bud since she's had less action than in canon by this point due to the youth guard and Taylor similarly hasn't really experienced enough to justify moving her canon budding point which is over a month away forward by so much. Which would only really leave some new shard poking around wanting in on the Apeiron data in which case you have to ask why would they pick Emma of all people when there's so many targets like the ABB conscripts.
Not buying this explanation personally. Joe is already a mercenary in public perception rather than a hero, and lord knows there are a laundry list of people who would like the S9 obliterated and could conceivably "afford" that revenge. Pretending to be limited to Brockton Bay is not going to make them seem like less of a threat than they already are in any way, nor would waiting for them to come to Brockton have any real benefits over just destroying them as part of some made up contract and posting a video(or doing it in some podunk town the S9 passes through). It's simply an overcomplication in search of justification.
I'm sorry, but that reasoning still doesn't add up for me.
What's the point in faking that thinkers can't predict him? You mean to say that he'll never act outside of Brockton Bay then? Or he'll wait for a more "worthy" occasion?
But the S9 are actually worth it.
What's happening is Joe's getting careless and not realizing the amount of damage those psychopaths could cause if they ended up fighting for their lifes inside the city.
And he's doing that for basically PR. Now he's both careless and irresponsible.
The S9 is gunning for him, and by extension, the brocktonites(?) due to his abilities. It's his responsability to shield those people from harm as best as he can.
He had a good plan: create an artificial battlefield that the S9 wouldn't be able to exploit in order to escape.
Now he's gonna let them roll in BB, the city which contains multiple gangs who would greatly benefit in a well-timed distraction.
Joe is a very big deal from the power lv he's shown off such as atks that are visible from other continents so there is a lot of panic about him. Just look at the alarms about Lethe using her power as an example. Those people such as in the prt have mostly calmed themselves by framing him under what they know of capes and thinker assessments so thinking they understand him. The key part there is they think he's passive unless provoked and limited to the Bay.
Moving out to crush the nine when they are not only as I covered multiple states away but in Legend's turf would freak them out and make them realise their understanding and thinker assessments were wrong which would have them panic even more than before. He also can't blame it on a contract because he has said he isn't accepting any right now and there isn't a known way to apply for them.
There is also the local situation with elements like Bakuda and Coil also having such views who would also panic over going to crush them now to say nothing of how it would have disrupted the charity event and recovery in general. Taking this extra time means he knows their ticks and secrets so can counter them, has let people have time to calm down and of course he gets more time to build up. He also isn't going to let them into the Bay or let them do anything once they have committed to final approach and it is undeniable they were heading to the Bay they are getting crushed without being allowed to do anything.
If you can't agree to that can you at least agree it was right of him not to go guns blazing hunting for them the moment he knew they were coming as in before finding out what the things his passenger was warning him about Siberian and Jack were especially since at that point he also didn't have their exact location and just they are somewhere within a large general area.
So the two dissenting voices went quiet at the moment they received a message and power boost? This certainly won't cause any problems.
I'm a little surprised Survey didn't manage to spy on Butcher's meeting with Uber. Even just knowing about the dead drops might have allowed Joe to sneak a dimensional tracker into one of the supply chain.
It was covered in the update but the good scrying devices require spiritual energy to make so most of Survey's monitoring is on them with what's left being on the sites the Empire is going to hit and the Empire forces that are going to hit them. The Butcher also ditched all the bones and things like them to appear as a normal civilian and specifically picked that time knowing Survey's attention would be on the upcoming fight.
It is worth remembering that Joe's sense of time is warped even before he got the ability to speed up the Workshop. In truth, the delay is overemphasized. Joe is impatient over the S9 "toying" with the droids, but if you look at it closely it probably hasn't even been an hour since Cherish and Shatterbird got directed towards the droid in question since it only happened around the start of the charity ball.
It's probably been more than that because of the Emma thing. Joe got alerted to her snapping after arriving to the event and things like running into Sabah but since then it's played out enough for them to have been waiting in the office a while, Joe to call the cops and Danny, both to get to Winslow, all the talking while they were there and then for Taylor to be in the hospital and Emma in holding. Notably for the last one the cop that was there told Alan to revise the time it would take him to get to the station from Winslow to over an hour due to how the roads are.
Joe also mentioned how he was glad the students hadn't spread the video around much during their lunch hour and then there's all the stuff that happened this chapter so all in all it's probably more likely to be in the ball park of 1.5-2.5 hours the nine have been messing around.