Ever since they fired the coach and Vivek talked about wanting a "fast pace" I have felt deep down Cousins days as a King are numbered. A lot of what is occurring kind of reminds me of what the Lakers did to Pau by hiring Mike D, you could tell Pau's heart was no longer in it and you can tell the same with Cousins he's not going all out anymore (plus unlike Pau he's literally had to team success on top of that to add to the frustration).
If Vivek long term thing is to have a a exciting up and down team than you should trade Cousins now while his value is at it's highest, winning was not enough at the start of the year Vivek wanted us to play differently, either way Cousins is going to demand a trade due to the fact he can't play the way the FO wants. If Vivek is not prepared to allow to build a team properly around Cousins I would seriously try maybe move him right now for like Russell Westbrook and they can start building around Russell as a "up tempo" team.