Simmons appears to be the only truly elite prospect in the draft, but this was known to be a draft with a lot of very young and very raw prospects, so some other players could still pan out (Ingram, Bender, Chriss, Maker, and even Brown and J. Murray to lesser extens fit that profile).
Yabu was a draft and stash for a reason, but some solid players were drafted after him and I have a hard time seeing him going 16 in a re-draft 5 or 10 years from now. There have just been far too many players behind him that are trending towards far better careers. LeVert, Luwawu-Cabarrot, Labissiere, D. Murray and obviously Brogdon all come to mind immediately. Guys like Whitehead, McCaw, Zipser, Siakam, Ellenson, Bembry, Richardson, etc. all look like they are going to be better as well and pretty much everyone drafted ahead of him is trending that way as well.
Ainge wanted a draft and stash, but it really looks like he screwed the pooch on that selection. He would have been better off just trading it for a future pick then taking Yabu.