FWIW, any interesting information about the JFK assassination is still likely withheld. The newly released files still have plenty of redactions and include a warning that they are not every record related to the case. You will probably die before seeing anything surprising come from JFK's CIA folder.
> in case of UFO, well - we have some smartphone video
We've got FLIR videos too, it's kinda what GOFAST et. al are famous for. Plenty more interesting than the Kennedy files, but that's just my opinion: https://en.wikipedia.org/wiki/Pentagon_UFO_videos
I also believe really interesting things, if there is any, did not leave a trace. People who send assassins towards presidents, if it did happen, probably did not write down their plans in detail. And any agreements between the power groups is most likely oral and "within certain understanding", likely built through generations of common interests.