The financial model that the BCCI wants does not involve less money for any of the Full ICC members (check the graphs you posted a few posts ago). The associate members are the ones affected. The BCCI was only to convince boards like WICB, BCB, SLC, ZC with bribes when the Big 3 was formed. Why would they abandon the BCCI now? They will get the same money with either model. They simply do not trust the BCCI.
In regards to the MOU, we don't have full details on what was agreed to so I cannot comment on that. If Ehsan Mani is making a statement to a reputable source, then I have every reason to believe that the CSA was also fooled by the BCCI. Especially considering that all of the boards have abandoned the BCCI.