I don't know I really don't think the classic trilogy changed in any substantial way to "fit in" with the prequels. Most of the changes had nothing to do with the prequels, such as Greedo shooting first, and the Monkey Woman being replaced by the real Emperor. The only changes that I can think of that were made to tie things together with the prequels were merely cosmetic. Boba's lines were merely re-recorded, not changed; Hayden's face was just used to represent the same character that was already appearing before.

The new Emperor scene in Empire pretty much sticks to the dynamic that was already there. With both of them talking about Luke as the son of Skywalker as if Anakin wasn't in the room with them, and both of them have Vader discussing Luke's potential conversion as if they could all be one big happy Sith family, with the Emperor giving that paused "yeah... I won't ditch you the second I convert Luke... Can it be done?" To me the meaning is about the same. Especially when you compare it to Jedi where the Emperor shows his true colors by ordering Luke to strike Vader down.

If you ask me, the prequels were made in such a way as to stick to the way the classic trilogy was already set up. It wasn't just some huge new thing out of left field.

Seriously how do you guys see things as being forced to match up to the prequels?

The classic trilogy is still mainly Luke's story. The only "mental stretching" I am aware of is that of actually accepting more information than what we already had in the classic tirlogy. Was it some kind of huge "mental stretch" to watch ESB and ROTJ after ANH? After all in ESB we find out that Vader is Luke's father. Who saw that coming? Then they had to "stretch" Obi-Wan's comments to Luke about Vader Killing Anakin as some kind of "point of view" convenience.

Then it's like someone was like, didn't Yoda say something about an "other"? Obi-Wan thinks..... looks off set where George is frantically writing out a cue card: "Leia is the other! That's the ticket" .

Are you telling me that's okay and makes perfect sense but we can't know about Anakin or else it somehow changes Luke's contribution to the overall story?

Sure Lucas was making this by the seat of his pants. Hanging everything off a fairly thin outline and fleshing out the details as he went. But that's nothing new, the only reason we didn't notice that with ANH, was because we didn't have any chapters before it to compare to. If we could just roll along with it for the classic trilogy, I don't see what's so different about letting similar things slide in the prequels.