I was under the impression all Oz Super Rugby contracts ran up to 31 December so's to allow players to be available for selection for EoYTs. In this instance didn't Cheika release Holmes, and Dennis, from their contracts early?
The contracts do run up to 31 December.
The departing players signed contracts with European clubs saying they were available after Super Rugby finished.
The ARU could have either enforced those contracts or released them and then tried to bring them back under Reg 9 but it puts the players in a difficult position with their new club either way.
On that basis the ARU has let them leave.
There was an article on rugby.com.au about it from memory.