I just hate when people change their opinion of a player just because of 12lbs, it's ridiculous.
As you said, we all saw his actual size and playstyle.
I'd argue that it's better that he was at 164 than 176 because he'll have an easier time putting on extra weight without losing speed. Being that weak with 12lbs extra would've been even more concerning.
While size obviously severely limits his defensive potential, we've seen last night that size doesn't matter if you don't put any effort in.
He'll most likely always be a negative defender, but his skillset and upside is the highest in his draft.
Imo, if Spurs don't pick Sheppard at #4 and Dillingham is available at #8, it's an easy choice. Can't miss out on such three level scoring potential when you already have a rookie guaranteed to contribute (Risacher/Castle in this scenario).