>Apple is the first major operating system vendor who had abandoned a four-decades-long tradition. Their new visionOS — for the first time in the history of Apple — will have round checkboxes.
So the death of the square checkbox they are predicting is only in the context of VisionOS. Apple’s HIG explain why this decision was made (my link), so I don’t think it is part of a larger trend and we shouldn’t expect it to impact anyone not using VisionOS, or other such headsets with eye tracking. It was done for technical reasons relating how the person will interact with the device, not style reasons.
After seeing everybody adopt the Android flat UI (win 10), i really think that stupidity is contagious.
Honestly, I wouldn't trust any modern Apple HIGs. After the UX butchery of BigSur they retroactively updated the HIGs to justify their decisions.