you are not missing anything
important, all they add are visual updates to old chapters. New environments, better lighting, that sort of thing. They improve a lot on the old renders and are nice to look at, but for me not worth yet another playthrough. Story-wise you can keep going and won't miss anything, otherwise it would again mess up the the saves if she introduced new variables. I think the main one will be the age retcon, I'll probably start a new game just to see how she digs herself out of that corner

Or just look up the changes in the script if I'm lazy