It's not rocket science who is a big gainer if it's 10 team tournament. Indian cricket fills the pocket of the ICC so they are big losers if something goes wrong, similar to 2007. Yes BCCI will also lose some but so are the other boards.
Given the risk involved, I don't think that the BCCI has anything to do with this. Their share from the ICC media rights for 2024-27 (38.5% of $3 billion, i.e around $1 billion) is only a fraction of the IPL media rights for the same period. Given this, I don't think that the BCCI will try to intervene in the tournament format. The risk involved is simply not worth it. I am 100% sure that Disney-Star is behind the new proposal. They have a feeling that they paid far more for the 2024-27 cycle than they should have and now they are trying to find some excuse to cancel the deal.