Yeah, I've got Wifi 7 set up and it's awesome. I've got a single access point, and I get full gigabit in my office with line of sight, and it auto switches to 5GHz or 2.4GHz when I move too far away. It's also great for apartments since it's more easily blocked by walls, there's way less interference from neighbors.
802.11a is over 20 years old, fortunately this law isn't talking about shutting down existing routers. the 6 GHZ is the next frontier to expand to, the military already owns the 7 GHZ spectrum... So the 6 GHZ is the one that can be expanded into. Of which origionally was planned to be made for the next generation of wifi... but now is going to be sold off to phone providers to use in the next generation of mobile networks.
So in short, our existing routers will continue to work as designed, but future routers will not be making any leaps forward.
Basically the choice between better faster wireless LANs, is getting killed in favor of better networks for cellphone services... of which the carriers will set the price on.
I have been using 6ghz for about a year or so now and I found it to be quite fast. MLO can be super weird sometimes and seems to get confused, but it works. (It's probably just a driver I haven't updated.)
WiFi is on all three bands. It's not so much what's newer vs older. Newer devices tend to support 2.4, 5, and 6 and switch between them based on quality of signal and support by the WiFi network. Higher frequencies like 5 and 6GHz are generally better because there's less interference.
Nah wifi was actually originally on 5GHz spectrum, with 802.11a. It came out shortly before 802.11b, which used 2.4GHz, and was objectively better...but component shortages for 802.11a devices made the inferior 802.11b more successful on the market.
Then in 2009, after 802.11b and 802.11g came 802.11n, which used the 5GHz spectrum, and introduced dual-band routers to consumers.
Most recently, 6GHz got allocated with the advent of Wifi 6E and Wifi 7.