(i'm swiss)
I believe there is no way in hell they could have passed this legislation if it included giving data of swiss citizens to the swiss government.
People here cherish their banking secrecy and it's still somewhat part of the national identity.
From a swiss point of view it was/is pretty much: The US is pressuring us too much, we'll have to give up banking secrecy, but only for foreigners.
If they didn't do that, i'm fairly certain it would have been shot down by the people with a referendum.