So if somebody finds Mozilla's embedded LLM summary functionality useful, they're not going to suddenly change their mind just because some stock crashed.
The main danger I guess would be long term, if things crash at the point where they're almost useful but not quite there. Then Mozilla would be left with a functionality that's not as good as it could be and with little hope of improvement because they build on others' work and don't make their own models.
The upstream might earn less, and some upstreams might fail, but once they have code switching to competition or local isn't a big deal.
That being said
"This could've been a plugin" - actual AI vendors can absolutely just outcompete FF, nobody gonna change to FF to have slightly better AI integration - and if Google decides to do same they will eat Mozilla lunch yet again
But yeah, Mozilla hasn't hinted at training up its own frontier model or anything ridiculous like that. I agree that it's downstream of that stuff.