Win10 store allows PWAs, and even automatically lists the ones it finds online (via Bing crawler).

https://developer.microsoft.com/en-us/windows/pwa

I find it all oddly ironic. Remember back in late 90s - early 00s, Microsoft was generally hostile towards open web and the (then only just appearing) web apps, because that undermined its desktop app monopoly? Here we are 20 years later, and now it's Apple and Google protecting their turf on mobile, while Microsoft is promoting PWAs to entice the mobile devs into supporting Win10.