It would be amusing if they enabled autohide by default, for those models.

I’ve got an Apple Watch Series 6 that has had an always on clock face for 5 years. In the flashlight mode in the lowest brightness I can see burn in, but nowhere else can I see any sign of burnin.

So oled burn in is not a totally solved issue but it’s not a big enough deal for me to care when the literal worst case scenario of an always on clock face does not cause real issues after years.