It does now... but it didn't originally, nor was the region locked. When it became locked , it trapped a bunch of commanders who had to put in support tickets to be rescued.
So, there was no "reservation " of that particular area earlier... FD already had locked regions like regor for their future content. But instead of using the areas literally set aside for that content (i.e guardians, Thargoids), they may locked a bunch of other regions instead.