The bearing seats (not races) on many frames are replaceable. LOOK uses replaceable seats on all of their frames. Some brands may not have replaceable seats, but if damage does occur, there are tools to recut the seat area and restore it. You really need to investigate how the frame is made.
That's one of several things I disliked about a Cervelo R3 that I owned very briefly. The bearing seats were made of very thin aluminum and permanently bonded to the frame. Not only that, the lower seat didn't even have full contact with the carbon. If any damage did occur, it would not be easily repaired.