That refers to 8.1 Update 2 (8.10.15148.160), but down under Versions, it mentions an NT 10.0 with an EoL date of January 14, 2020 and the footnote says:
Originally scheduled on December 10, 2019, but delayed following one more security update due to the release of iOS 13.3. Supported until January 10, 2023 via the paid Extended Security Updates service.
And even then people could still hold onto their old phones (though I'm not sure if Windows allows bootloader unlocking and custom ROMs as readily as Android). I keep mine until the battery gives out, many years after purchase - even if only as a media device after removing the SIM, like to control casting to my TV. 8 years is actually normal for me.
Anyway, you are right I bet they were referring more to laptops with a desktop Windows OS.