If you make the AI home mobile, then in order to retain the homeworld assault feel, you'd have to make all of the defenses travel with it. I'm not super keen on such a large collection of powerful objects being able to move at will. It would be strange to fight. Might be worth fiddling with at some point post-EA just for novelties sake if nothing else, but I certainly wouldn't expect it to become standard behavior.
That wouldn't an idea I would support myself. However I can imagine a game mode (or MF, or option, or something) with no AI Homeworlds, Core Worlds and Core Guard Posts, but instead a MkV fleet with Dire Guardians and Hunter/Killer(s) around a mobile AI Home Command Ship.
I imagine a sort of new class or twist of the Dire Guardians providing invulnerability to their leading Home Command Ship, similar to what the Core Guard Posts did, with interesting powers just like them (Teuthida reclamation, Wrath-Lance-like weapon, Shredder Drone Spawner, etc).
As I said, not an idea I would personally support. Maybe I would play it once to try, but that wouldn't be my default playstyle, I guess.
(I imagine a MkV fleet of that sort would be used by the AI in early game to "blitzkrieg" the Human background factions.)
What was the topic? Scouting? Oh...