That is not a official aweb support page, official page is gone for long time ago. Developer files and lates sources are allso gone???
We have such a tiny community that OWB port for UEA use wouldn't be good thing, it woun't benefit real amiga users.
It wouldn't hurt Classic 68k Amiga users if a port of OWB were ported to UAE. UAE is nothing without AmigaOS1.x to 3.x running on top of it, so porting OWB for use on AmigaOS1.x to 3.x when run on top of UAE "might" benefit users of Classic 68k Amigas, if they have an fast 68060 & RTG graphics card.
But I agree that anyone running UAE to run AmigaOS would be better off just switching to the host OS and using what ever modern browser they have for that host OS to do their browsing and downloading of files, then transfer them into the UAE Amiga emulated OS for use.