as for granting players immunity it looks like we can thank the players union for that one:
Manfred said he originally told the Players Association that the league wouldn’t rule out disciplining players, but said he got pushback from the union.
“The union indicated to us that would be a problem,” Manfred told reporters Tuesday. “We went back and suggested to them we would give them an initial list of people — players — that we would grant immunity to, preserving our ability to discipline other players. And the union came back and said that players would cooperate only if there was blanket immunity. Because we were at a bit of a stalemate, we knew we needed player witnesses, we agreed to that immunity agreement.”
Manfred also said the league wouldn’t have gotten as far in their investigation if they did not reach the agreement with the union.