For me, I'm not a big Stan X Wendy fan and I think for me it would take way more than just apologizing for them to have a healthy relationship. An apology would be the first step of many and I think that a story where they try to repair their relationship but both come to a conclusion that it's too little too late and that they realise that they shouldn't be in a relationship with each other would be something I'm not against.
I prefer Kyle to forgive and forget Heidi (as well as forgive himself) as in he doesn't hold any bad feelings towards her but doesn't talk to her ever as he realises it is healthiest for him and Heidi to just move on. I also never liked Kyle X Heidi because Kyle comes across as a 'nice guy' meaning a person who acts nice to get his own way because he feels if he does the right thing, he can get a love interest as a reward. SuperHard PCness only pushes the idea further that Kyle isn't a nice guy he is a 'nice guy' since he got Canada nuked. I've always hated the exchange in 'Spatty Tomato' where Kyle saids 'I will never date the person you have become' to Heidi because Kyle has gotten millions of people killed because he couldn't get his own way. At this point, Kyle is way worse than Heidi (Cartman or normal version). Honestly, you could make a good case that Cartman is better for Heidi than Kyle because of SuperHard PCness alone (although I really really don't want to see a Heidi story with either of these characters ever again). I mentioned that Kyle X Bebe is a ship I much prefer as it would probably have less of Kyle's toxic masculinity. You can still address it but it wouldn't feel like he is actively getting rewarded for it. I think it is way more likely to happen than the Heidi story that I would prefer with one of the main four boys. I prefer that future Heidi stories that are well away from Cartman and well away from Kyle. Honestly, I like the idea of Heidi stories having nothing to do with any of the four boys.
I'm not going to talk about Kenny as I explained what I think about him in a comment in a previous post.
I would prefer the broship to not return for a season. I would want it back but it would be interesting to get a season of these boys separately and what they would do without the broship. Although this is another case of what I would like is not what I think will happen.
I like the idea of Cartman choosing between the new and old group. I think it would be more effective if for an entire season the broship hasn't returned.
I've mentioned Bebe and Heidi already so I will talk about other ones now. I want Wendy to get more screen time whether she is with Stan or not. I think she is a great character especially outside of her relationship with Stan. I don't care about any of the others but I'm not against fleshing out other 4th-grade girls. I don't think they are going to flesh out any of the 4th-grade girls this special as there is already a lot they could do.
I wouldn't want it in either of the two specials coming this year but I do like Tegirdy farms eventually getting burned down and doing a mystery of who burned down Tegirdy farms much like the episodes 'who shot Mr Burns?' (part 1 and 2) from 'The Simpsons'.
I don't care much for Shelly as a character at all. I don't want to write about her. She has no excuse for being a poor character.
Anyway, those are my thoughts on your predictions and what you want. I hope you find my thoughts interesting even tho you probably will not agree with a lot of them.