I think Spurs don't really care about their roster after their main rotation players. Some teams try to have a good 12th or 13th player and have interesting two-way players, Spurs just don't care. That's why they keep trading away second round picks, that's why they wasted a roster spot on McLaughlin at the end of the season, that's why they keep Minix despite him being injured for the rest of the season...
If everything goes well, Spurs main rotation should be after few months:
PG: Fox/Castle
SG: Harper/Castle
SF: Vassell/Bryant
PF: Sochan/Barnes
C: Wembanyama/backup C
I can see Spurs wanting to give a shot at that team and wait the trade deadline to see if an adjustment is needed.