I wonder then if we can expect at least 5 servers per region
I guess it's technically news but, not really at the same time as it was pretty obvious that they would do that, as with it not overlapping... it's an entirely different account, of course it wouldn't overlap. Same as PTR/Beta/WoW2/WoW3 etc don't.
At least a couple of the different realm types (PvE, PvP, RPPvE, RPPvP) each per region. Not too many though.