EDIT: What I could see, though, is them getting McDiarmid to voice Palpatine for the upcoming final batch of Clone Wars episodes coming to Disney+. If they already got him in the booth for that, it’d be easy enough to have him read this one scene from Rebels.
That’s what I was referencing in my post.
Although honestly, if they were willing to pay him for 2 or 3 days of vocal work, they probably could have retrofitted him into the old Clone Wars episodes too. But I agree with you that such a scenario seems unlikely.
RE: the other examples of tinkering: That decision to re-do the fanfares is so weird, in retrospect. I don’t understand why they even tried it, or further, why they thought that edit was a good idea.