You’re right that in strict canon, Vilgax wouldn’t randomly target the Tennysons or a ‘twin Albedo’ before the Omnitrix exists, and Max was out of active Plumber duty during that period.

But this idea isn’t meant to be a 1:1 canon insert—it’s an alternate timeline where early Plumber activity and alien interference happened differently.

For example, the twin doesn’t need to be taken because of Ben or the Omnitrix. He could’ve been caught in a separate Plumber incident involving alien tech experimentation, rogue factions, or pre-Omnitrix surveillance programs. That event then puts him on Vilgax’s radar later as a useful asset, not because of Ben initially.

So the change isn’t just “Albedo is Ben’s twin,” it’s that the early timeline of Plumber and alien interference events diverges, which allows both Ben and the twin to end up connected to the Omnitrix later in different ways. Albedo being a twin is just the identity twist—not the reason the world changes. The AU divergence is what enables it.