Personally, I don't think you need to go all in on retconning this run. Like pretending it never happened at all is better than forcing some retcon onto it that doesn't make sense the more you think about it. In terms of "fixing" MJ, all I want to see is good stories about MJ. They are not going to be tainted in my mind just because dead language happened. All that was OOC anyways. The most that I would want to see is a story at the beginning of the run arguing why PeterMJ should still get together in spite of everything that happened. Like it's been mentioned before that Aunt May should probably be pretty pissed about the whole Paul situation. Especially since she doesn't know that MJ was stuck in an alternate dimension for 4 years. So have a story where Aunt May is against the two of the coming back together because of all of that. And show how they work through that situation together. Or like I said before, just ignore dead language cause it sucks.