He's got great size and hands. Maybe he's hearing things that aren't out there on mock draft boards, but I'm wondering if this is a case of being done with college/age and striking while the iron is hot. The timing is interesting and the rumors have been out there, but doesn't seem like he's interested in getting a draft grade to make his choice and just ready to be done. Tyler Batty was in a similar spot with similar buzz last year and waited to get his draft grade before making his choice to come back which seems to have worked in his favor.
I'd have to think he could probably get the same or better money in NIL as he'd get as an UDFA or 6-7 rd pick which is why I think less to do with draft stock and more to do with now or never because of age/mission/family