I have no more insight here than anyone else except that he has no influence in my neighborhood (Which frankly isnt exactly a MO neighborhood).
I can only guess (This is MY THEORY not discussed with anyone else) the only reason Avi Weiss has not already been kicked out of the RCA is because some feel the damage might be greater.
By keeping him him, they can put at least some checks on him , if they kick him out he becomes a Martyr and makes his own organization stronger and then there is no way to stop him
He DID back off from the Rabbah due to pressure from the RCA, if he is on his own he would not have to back off and could ordain as many Rabbah as his likes, Being part of the RCA they can pressure him to stop some of his other “innovations” but on his own they cant.