Coaches used to do it all the time in Tark (haven't paid enough attention recently to know if it's still happening). Since no promises are being broken, although his WE will almost certainly bottom out, I highly doubt that he leaves (like 99.475% confident). I never had a player leave and never remember any of my (then) ACC or Big-12 conference mates complaining about a player leaving in that scenario either.
The draft thing is a little trickier, not 100% on that one. Never had one declare early for the draft after his "redshirt" season doing it that way, but still not extremely confident that he would "automatically" not declare either (sorry if that's confusing).