WiFi networking basics, no mention of known backward compatibility device issues.
Here's a good video from Microsoft on WiFi 6 technology. The newer/mature technology will bring better, broader and reliable signaling. One thing our technicians and clients will tell you is WiFi 6 technology is not backward compatible with older or even some WiFi/IoT devices or work with some ISPs (Internet Service Providers). In other words, your doorbell camera, some branded cameras/Security systems like Ring, Vivint, Simply Safe or Arlo, thermostats, Amazon Alexis, etc