It was probably a complicated dance. Cabal had options to succeed Jong Il. Jong Un had to secure a position. Looks like typical dictator succession wars from the outside. Cabal ends up with few options other than Jong Un.
But Jong Un doesn't have full power over his nation. That is a farce. There are smaller political parties and affiliations. The nation is deeply in debt. There were deliberate industrial controls put in place to keep NK useful, but dependent.
Jong Un probably overplayed his role, deliberately, leading up to now. The cabal doesn't have iron clad control. Jong Un was probably pissing them off with how eccentric he was getting - but what could they do about it?
The MSM has been all over the fucking place about this when they should be the investigators. Kim flips and drops his mask - and the media doesn't have anything to stand on. The contingency the cabal was leveraging against both NK and U.S. evaporates beneath them.