in the MLS, player contracts are iirc with the league, not with the team. That's why clubs can trade players (like in other American sports leagues).
The draft is interesting because of all the rules with registration & rules -- Inter Miami got in trouble for breaching the salary cap recently and lost money and draft picks
theoretically they chose not to protect his rights in the expansion draft so they *did* have a choice but the thing is that they (St Louis) selected his rights to begin extension talks. He still is under contract with us until June iirc so I don't know how that will work