Given the way they've handled upgrades recently, I expect both options to be available. They'll probably do something like they did with the MG Turn A wings. You can get the wings separately, or get a version packed with the V2 and maybe a special finish on the kit or special decal set. I think the upgrade kit is 100% certain unless they need to remold huge parts of the frame or something to accommodate. Don't see why they would. Maybe that's me being too optimistic.
I'm buying V2 AB however I can get it, but that doesn't mean I'm going to be happy. Haha.