Okay cool, thanks for making a mock-up of it!
I see what you’re saying. It feels weird to cut right when Finn starts talking. I guess you could argue Finn could mean “they’ve done it” as in they’re actually invading a planet not in First Order space (although Jakku wasn’t either).
Another interesting thought I had about why no one is running might be because no one has seen TIEs (nor a Star Destroyer) in possibly 30 years, so everyone could be stunned by what they’re seeing. So Finn could be saying “they’ve done it” in the sense of they’ve built a new fleet, explaining it to Han. In a way, the Empire has returned. But I know, that is just me pulling straws.
The only other thing I can think of is not have him say anything at all besides “Where’s Rey?”. Just have him run up, cut to sky for a second, then cut back to him looking around for Rey before he asks where she is. Because if you think about it, Finn is sort of pulling a Ric Olie since Han probably knows exactly who it is.
Sorry for the long messages. Just trying to think of different ways to make it work, because I really like this idea of moving the Hosnian destruction until later as well.