I haven’t flown with anyone that is for the mandate, me included.
Many of the guys I fly with (more so than not) are already vaccinated (me included) so even though they aren’t for the mandate they’re not losing sleep over it.
I know of a few who aren’t vaccinated that have already made plans to do so. That doesn’t mean they’re happy about it though.
I don’t know of any personally but have heard of a few guys that are going to quit over it. I think they are a small percentage.