I know a lot of people harbor irrational hate for Christensen. But there's absolutely zero reason to recast (unless Christensen refused to do it for whatever reason). Recasting Obi-Wan and Han was obviously unavoidable. But there's no reason to recast Anakin in light of the change made to that last scene in the latest editions of ROTJ (yes, everybody harbors hate for all the changes too, I know...).
How good/bad fans think he was in the role is immaterial. It wouldn't be a large role, especially if it's non speaking as you're speculating it could be. If you see Hayden, you know "that's Anakin". If it's some random dude there could very well be a moment of confusion for audiences which would be better to avoid if possible.
So, agree to disagree. If they don't/can't get Christensen, I'd rather they don't bother.
There's no irrational hate here (in my case). Go watch him act in another movie and tell me he's the best person (or even FIT) to play Anakin Skywalker (Darth Vader). All you need to do is name drop Anakin and/or provide contextual clues as to who he is and why he's important. We're dealing with BRAND NEW Star Wars fans here for a new generation. I know a ton of people personally who never saw a single film until EP7 and loved it.
Most people aren't going to watch EP8/9 and say "hold on a second, where's Hayden?". I think it just makes the most sense to hire the best person for the job and Hayden is clearly not it.
Irrational is "it can only be Hayden". That's a minority speaking and won't affect anyone other than people who wanted it to be him since.. he played Anakin in the prequels. Or because they like him. He had no outstanding scenes or performances to rationally warrant excitement for his return.
They need to cast for the best people for the job, especially if the underperformed in the PT. I'd say there's much more of a pull for McGregor to come back from fans, and even still, this is the minority of fans.
I feel like the pull for McGregor is much more rational since he did so well in the PT and I'd say most people would agree he overperformed with the content he was given.
Hayden on the other hand did not.