FATCA only guarantees the transfer of tax information to the US, and not the other way around. Since the US is the biggest tax haven in the world (for non-US citizens/residents), it's higly doubtful they would ever sign any agreement like that that would geopardize their tax haven status. The banking lobby would never permit (especially under someone like Trump).
As for CRS, US doesn't appear in the list of signatories: http://www.oecd.org/tax/exchange-of-tax-information/MCAA-Sig...