Trump is probably on the list, so he has to protect that. The Democrats had it during their entire presidency; even if they didn’t want turmoil during their time in office, they could have released it after their presidential defeat and before Trump took office.
Checkout this podcast which has an interesting take on this: https://www.youtube.com/watch?v=o069oHLvDkg
Basically, they conclude that we all know who is implicated already and this is just a lot of meaningless distraction. They go on the point out that people from both parties are involved, and that even know we know by in large there has been no consequences and there is unlikely to be any.