The price however, isn't indicative of a 2022 product...

Do they? The new Apple monitor supports 120 Hz.

The first sentence doesn’t: “ Since writing about Mac external displays in 2016, not much has changed.”

Quite a few Mac-oriented 5K and 6K displays have been released in the last few years. LG, Asus, Dell, Samsung, Benq, Viewsonic. Maybe some others as well.