In-season coaching changes are hard to predict in the NHL. There were zero of them last season, which was a rarity. This year, there have already been two so far (Joel Quenneville and John Stevens) and they're usually done for a similar reason: the group is underperforming and teams want to salvage whatever is left of the season.
Chris Kunitz was part of a mid-season coaching change as an alternate captain with Pittsburgh in 2015-16 when Mike Sullivan took over for Mike Johnston on Dec. 12 after the Penguins went 6-6-3 following a 9-4-0 start. It was probably time for a new voice there anyways, but the Penguins lost four straight games in regulation to start Sullivan’s tenure as coach.