I think Stross could still do a crypto parody or something, in theory. I don't think it's likely, but he could.
I mean, he has set up other characters to do stories Bob isn't suited for, he's talked about writing short stories until he figures the next book out, etc. The series has had crazy stakes from the start (remember the Early Installment Weirdness of the universe eating ice giant thing?), and there's still zany low level nonsense going on now, so it wouldn't be out of place in the world that he's created.
After all, a lot of Index was street level brawling against Black Chamber vampire goons, baddies chasing the President, and American radio people reporting feral dragon attacks. And Stacks was basically "vampire and fairy tag-team a bunch of elfin knights and weirdass zombies on the World's Worst Meet The Parents Date".
<shrug> I'd expect Black Chamber!America to at the very least depopulate Africa and South America with nuclear carpet bombing, as well as conquer Canada and exterminate the population. For starters, before the supernatural aspects even get involved. Less real world, more pre-Great-War Fallout America with Lovecraftian horror instead of retro-scifi tech.
They can't use nukes willy nilly in TLF any more, the stars coming right means there'll be huge necromantic energy surges from the deaths which'll spur on the worlds ending or something. It's in one of the early ones. Might be where Tamsyn Muir got the idea for the Locked Tomb series. Besides, their long term plan was to eat the whole world or something for their Singularitarian Wasp God or whatever, so I think they've left RL politics far behind. Which is a shame, really.
Anyway, the funny thing* about Laundry/Black Chamber comparisons is that Bob will tell you all about how historically, the Americans used to be reasonable but then
something happened, they internally rearranged themselves a few decades ago and re-emerged as these cackling monsters who've been blatantly subverted by the powers they work with, not like us good old British folks, oh no…
And then he'll casually make
jokes about how the Laundry's Board of Directors have vanished from the physical world and nobody's seen them in decades before walking past the zombified corpse of a guy he used to work with to give a report to his boss, the Eater of Souls.
I mean, by Labyrinth Index there's pretty blatantly no difference, though you could argue that was partly a descent into evil rather than a reveal. Mhari even has a We're Not so Different moment talking to a Black Chamber boss. And by that book our MCs are a would-be financial criminal turned member of the House of Lords and a cop from the same Metropolitan Police mentioned in the OP, which is just far too on the nose for me to think they're meant to be straight up heroes any more.
IMO this is at least in part of his computer science career ending sometime during the 00's. One thing I noticed is that after the iphone full of spells during Apocalypse Codex there wasn't anything new in regards to compsci parodies or clever applications of demonology. It wouldn't surprise me if he ignored the latest in the field to focus more on geopolitics but with elder gods.
I've noticed that went away too. Mind, there's a bit in Nightmare Stacks here and there. Alex runs a sort of automated loop counter in his brain to counteract the vampiric salt-counting weakness, and later uses it to perform massive-scale demon summoning to slaughter one of the villains. There's also a thing about how they tried to give the CCTV basilisk guns automated targeting, only they train them on a corrupted dataset and can't identify the enemy, so then the fancy but untested AI overcorrects by just shooting at
everything and gets a load of innocents killed.
But then Nightmare Stacks was very much a throwback to the early series. It even has a Nasty Ambitious Female Villain, though this time it's an alien dragon riding warlord swinging a power mace instead of a Shrewish Middle Manager Who Doesn't Code, so that was a nice upgrade.
* I tell a lie. We're all sleeping on the
really funny thing about the Black Chamber, which is that they're literally the Deep State out to get the Real President and book 9 is about Mhari forming Qanon.
EDIT: Oops more people have posted since I started writing