Yes, could, assuming that the AP supports it -- and nobody seems to be in a big hurry to implement that. After all, 802.11h has been standardized since, like, 2018 or so, with exactly zero mass-market support so far.
Absent a proper 'how to join the local Wi-Fi network' story, IoT connectivity is converging around LoRaWAN anyway.
As I said, I like the 5GHz support, but spinning it as 'power efficient' is a reach.
The problem is, until nearly all networks support it, nobody can release a product that relies on it.
If you buy a battery powered IoT doorbell and it's box claims a battery life of 1 year, but then the battery is dead in a week because your router doesn't support the right 802.11 extensions, are you going to blame the router maker or the doorbell?
Really? Don't think I've ever seen a LoraWAN product in the wild.
Lots of ZigBee stuff, lots of ESP8266-based WiFi stuff (which generally requires a crummy phone app to perform the initial WiFi setup), and a bit of Insteon stuff hanging on despite whatever the heck is going on with the company.
LoraWAN sort of dominates agriculture IoT (the S is for Security) market. I guess it depends on your target area, but it is alive and very well.
Even if you aren't a blockchain fan, Helium[1] is still alive and well. It is helping spread LoraWAN even further. I live in central KY and have several helium networks near me. Never in a million years did I expect blockchain to end up on farms in Central KY, but here we are.
I have seen farmers using LoRaWAN, and The Things Network has pretty good availability in Europe. It's not really for smart home uses, more industrial/long range applications.
Portions of 802.11h like DFS are widely supported by pretty much all manufacturers. Without DFS, many of the 5GHz channels are unavailable for use, so there are strong incentives for manufacturers to implement support.
Other WiFi features which allow power savings like APSD (802.11e) have widespread support too.
I see lots of LoRaWAN for sale, but nothing really using it. There's 802 series standards for WiFi-compatible-ish packet switched radio on the ISM bands, I suspect that will get more traction once it's finally in real products.
Absent a proper 'how to join the local Wi-Fi network' story, IoT connectivity is converging around LoRaWAN anyway.
As I said, I like the 5GHz support, but spinning it as 'power efficient' is a reach.