You'll get some guys in D3 who were throwing 84 MPH when they were recruited as a rising HS senior, but by the time they are Juniors/seniors in college they are throwing high 80's. I would say that it is rare for a D3 pitcher in my neck of the woods to be touching 90's consistently, though.
I do see others at lesser D3's(baseball wise) who are still throwing around low 80's.