I take it, then, that you can't just switch between them like Deoxys (or even Arceus' types). Or perhaps you can... it would add a whole new dynamic to team-building if you could switch between level-up move lists, thinking about it.
Oh, and I probably don't need to remind anyone of this... but for posterity, remember that gen 1 had four machine Pokemon and a blob of pink goo. I wouldn't consider Rotom's new forms a stretch at all.