It is important to remember when athletes say they don't want to play somewhere or there are strong indications that they are resistant due to influence of their agents. You may or may not recall Brian Shaw and the struggle to get him to suit up in Boston, or Jon Berry sitting out and refusing to play.
It seems that Dunn just doesn't want to be drafted by a team that has a logjam of guards.
Boston is clearly that place. However, drafting Dunn simply means moving one or more of the guards.
Dunn not releasing medical reports and not scrimmaging may be designed to "maintain" his draft stock. Dunn is a 3-9 pick range
(Bender, Murray, Hield, Brown, Chriss and Poeltl)
Consider this, Ainge decides he really likes him, after all he scouted him. He decides to take him.
All that means is that he is going to package up some of the other players and move them.
Another option is that Ainge talks up Dunn, to drive his price up and then drafts for someone else.
There are many possibilities. Ainge needs to keep his cards close to his vest.
But don't think we are Done with Dunn.