Probably unpalatable to industry. Do you imagine ASUS would want their newest 2020 router to only be Wifi 2018?
The rise of this sort of branding is very intentionally to make comparison possible, as you don't really know anything about the Ultra Frequency Crystals and why their competitor doesn't have them, just buy whichever ones have flames and a dragon on the box and it'll work itself out.
The other half or more of the market already doesn't understand the existing versioning scheme. If you print the version in small print on the back of the box, they'll be no worse off. Or simply elide the first two digits and they won't know it's a year-based scheme.
And who's to say they can't do a yearly release cadence? WiFi 20, WiFi 21, ...
Our 2020 router supports wifi 018