We don't need to go "DON'T SAY ANYTHING TO KYUBEY! ONE WORD, ANY WORD, WILL RUIN EVERYTHING!".
It's bad news, yes, but not quite that bad. If it was actually that bad, we would be wanting to avoid ANY use of telepathy, which is silly.
Yea, "hooking up" Hitomi is not important enough to seek out Kyubey over, but if we meet Kyubey any ways (either by chance or for something that is important enough, like grief disposal), I see no reason not to bring it up as a suggestion during that time.
Worse it could realistically do with that is to say "Nope, not worth it", or "Sure, but only if you do X" at which we would almost certainly say "Nope, not worth it" unless X is super utter trivial and harmless in pretty much every way.
Also, we aren't really at any additional risk of it trying to using that information (that we want to get Hitomi "hooked up") against us; it almost certainly knows this from when we tried to "ping" Hitomi already.
EDIT: That said, if we can find a Meguca with telepathic powers and can recruit her, it would almost certainly be worth setting up an alternative "network" that is not Kyubey run. The less info fed to the white rat, the better and all that, especially when we don't have to give anything up to do so.