If they have post-ending DLC, which I think they set up a strong possibility for, it will probably lead you to Arizona no matter what, with the three "continuation" endings (The Star, The Sun, The Devil (return to Earth)) mirroring the three life paths (Nomad, Street Kid, Corpo). There's enough lore in the game to strongly suggest that
StormTech and their operations in Arizona might be V's chance to find a "cure", so-to-speak. All three endings, I think, provide a strong likelyhood of V finding them. The Aldecaldos in the lore already have contacts with StormTech. We know very little about Mr. Blue Eyes... but given the vague implications, I'm willing to bet he somehow will end up being connected to StormTech. In "The Devil" ending, it's less clear how you might find your way to StormTech. Maybe from working with Arasaka you get contacts that lead you there, maybe you reconnect with the Aldecaldos in Arizona, or maybe something else.
In any case, I don't think they'll make ending-specific DLC, but I do think there's a
very strong possibility for them to make post-ending Arizona DLC.