I'll say that last year after his first couple starts, Hendricks' success felt pretty real and earned. I think he got lucky with some at'em balls his first few starts, but quickly knocked off the rust and settled in. The data backs this up too, from 6/28 onwards he had 18 starts with a 4.13 ERA and a 4.09 xFIP. And as you mention there were real changes to velocity and approach (and obviously health) which make you think last year was pretty real and not just a dead cat bounce.
I understand the projection systems not liking him anymore, they shouldn't, but I also think he's the easiest call on the roster for exceeding those expectations. Prime Kyle isn't walking through that door, but if he can be the #3 starter he was last year it makes this pitching staff pretty feel much more legitimate.