The engineering manager has been on leave while all this has been happening. I'll be bringing up my concerns when he's back next week. I'm sure he'll be quite understanding. He did reply to one email to point out that there isn't a lot he can do because the new PM reports directly to the CEO, not to him.

Basically the engineers will have multiple bosses. The engineering manager for technical direction and the project managers for task priorities and day to day management.

I think there is still a role for me to play as a senior engineer to mentor and assist the other engineers on their projects but it's harder for me to do this when I'm out of the loop.