I really do think it's way to early to say that's how it will play out.
I listened to Curran and Perry's podcast and they said Hoyer is good news for Jones, he's being brought in to mentor Jones in a way Cam probably won't and Stid probably can't. Apparently we have no QB coach, so there really isn't enough time in Josh's day to be OC and QB coach and integrate all the new players the team has added.
The issue with Cam is he still thinks he's a starting QB and presumably won't take well to being benched if the team decides to go with someone else, whereas Hoyer is already used to being a backup.
Personally I think they keep 3 QBs and the most likely set is Cam, Stid and Jones but if Cam sucks it'd be Jones, Hoyer and Stid (maybe not in that order). Cam is easy to cut, a lot of his pay is in per-game bonuses. If he's too much of a primadonna he'll get cut. I would not be all that surprised if Stid gets traded, but we've seen no indications that the Pats are ready to do that just yet.