He and Sami do have the usual soap twin thing where they can sense each other. They always did, going back to when the characters were babies. They're protective of each other.
However, Eric will absolutely choose Carrie over Sami if he thinks Sami is in the wrong. He helped wreck Sami's wedding to Austin because Austin really loved Carrie and Sami was faking amnesia, lying about Will's paternity, etc., to make the wedding go off.
But it's been so long since we've seen Eric that there's no way of knowing if he'll be anything like the character Jensen Ackles played.
