There's nothing in Ash Knight that indicates that Corwin is already living in Nekomikoka. As things are resolved Interlude 2 he's certainly going to be moving in with Utena and Anthy but at that point he's still getting his life back together after the time in Asgard. If anything, he probably went back to his New Avalon apartment in the meantime while preparations for his move (and the wedding, and Anthy's baby) were underway. Even with the resolutions reached in Interlude 2, Corwin seems to be taking his time in the move to do things right.