the docs regarding HTML export is very old as that feature is unsupported by Unreal Engine since UE4 days. They abandoned web export basically, because the features they needed did not exist on the web platform back then. The post is about a 3rd party attempt to bring those experiences to web through the use of WebGPU - Unreal Engine 5 by itself does not support it (yet, if ever).
I could see Epic maybe giving it another go, but the features would be limited. When people hear UE5 they think of the new flagship features like Lumen and Nanite, but those are built around API and hardware features a few generations ahead of what WebGPU currently offers. Nanites software rasterizer, for example, really needs 64bit atomics to be at all viable.
That's the old UE4 web target, which Epic deprecated way back in 2019. OP is about a new UE5 web target developed by a third party rather than Epic themselves.
https://docs.unrealengine.com/4.26/en-US/SharingAndReleasing...
https://github.com/UnrealEngineHTML5/Documentation