It seems Manfred has talked with some owners about that rule suggestion.
Apparently he wants to allow once a game to have a golden at bat where you can give one player who already is in the line up an extra at bat out of turn.
https://www.mlbtraderumors.com...n-a-little-buzz.html
The thought is that you can basically play it like in mlb where you can give the ball to your star to hit the buzzer beater to create a more exiting moment at the end of the game.
Manfred said there are no plans to introduce this yet and that it is still at the idea stage, so probably making it publicly was to test public reaction.
Unsurprisingly there was a lot of negative reaction to that. Proponents say that in nfl and nba the ball also is in the hand Patrick mahomes or Steph curry and not in some random bench players hand and that a baseball game ending with the slappy #8 hitter grounding out to end the game is a bit lame but traditional baseball fans see that as a mockery of the game.