I know this is most likley to be me putting two and two together and getting 27, but after all wild groundless speculation can be so much fun.
Over at Newsarama there was an interview with Steve Wacker on matters 52.
Here In that interview he said
“would have been free to show Hawkgirl returning to Earth in any manner they wanted. 52 came along pretty early though, so they never had to worry about it to the best of my knowledge…you do know that One Year Later St. Roch is inhabited by giants right?” So on no other evidence than a joke throwaway line I confidently state that we now know the home town of Colossal Boy and where all the other giants on Earth live.