Forgive me; I'm melding two things. There's the consequence of FATCA versus an IGA, and FATCA itself, in the event of information not being furnished as required under FATCA, could involve account closing. It is not specific to your point about why information is provided to the CRA and over to the U.S. versus directly to the U.S. That is about privacy concerns.
On May 29th, 2014. See this statement in context.