Menzinger
Kessel4LadyByng
Speculation, but there are events that make this seem very probable. After the playoffs Dubas did not say if Babcock would be back or not (likely wanted him gone but had to get approval). A week or so later, Dubas says Babcock will be returning (likely had meetings with Shanny and other stakeholders and they wanted Babcock to stay due to 3 straight playoff appearance = money). Chris Johnson has said that people in the organization loved the way the Leafs played Boston in game 5 and obviously thought Babcock was capable of getting them to play like that consistently.
Then there were a lot of cryptic tweets, likes or things said in the media by Babcock and Dubas that pointed towards them not having the same vision.
Then of course you have Keefe, who was being paid a large amount to stay with the Marlies because he has been Dubas' guy since the OHL and it was only a matter of time before he took over with the Leafs.
Feschuk at the Star straight up said in a coulmn in the offseason that Dubas tried to get a coaching change in the summer but was overruled by those higher in the org (either Shanahan or the mlse board).