Sounds like his dad, if it is him (and the pic looks just like an older Jerimiah), is saying the same thing most of us are thinking.
What does he really benefit from marginally improving his stats by returning to college? Especially when he can develop in the NBA and GLeague minutes. Without the grind of college, risks of injury or not improving significantly, and having much more freedom. While playing against the best with better coaching, 24 hr training and staff, better resources, nutrition, etc. And I would argue LESS grind as there would be more movement and flow on the court in the NBA than the SEC or ACC or B1G.
As a G, he's not going top 5 this year or next. Buddy with his SR yr and size and 3 pt shot was #6. Trae leading the country in scoring and assists was #5. Either year, his position is probably in the #8-#12 range, with possibly high as #6 and falling out of the lottery to the #20ish slot. He could drop further but I think his potential keeps him in that range. With the real money being in the top 5 or in the second contract, to the original tweet, don't see a lot gained by deferring the draft.
I have not seen one good argument yet on why he should return to college.