This is a big part of why I've been saying I've come around to the view, recently, that he is more than likely to stay. Obviously the double-major announcement helps the comfort level in that prediction too, as well as the "unfinished business" feeling from this season. Even if there weren't the draw of playing with MP3, which I actually think will be a big pull, there's no doubt in my mind that Mason greatly enhances his probable draft position by staying another year. (That is partially due to who's going into this year's draft among bigs nationally, and partially on the opportunity to develop certain NBA-critical skills next year, plus enhanced visibility of being a probable pre-season All-ACC pick...) I hope that (draft enhancement) statement appears in some form or fashion in his exit interview (along with the specific "draftable" skills the staff plans to work on with him over the next 12 months.
I'll be surprised, but not shocked, if MP2 leaves. With Austin, I am much less certain, especially since I strongly suspect that he and his dad still don't know either.
For all of those pointing to the criticality of this recruit or that recruit to next year's success, the reality is that almost all years the decision as to whether certain current players return is almost always a bigger determinant of success the following year. Experience pays dividends.