Either way, it's evidently the end for web design in XPress. Pity. It could have been good.
No, it could not - certainly not with the limited resources Quark has to throw at it.
Building for the web has become ever more complex. Flash at it's time was a nice way for print designers to cheat complexity by designing for a sandbox environment (and at the same time ignoring a lot of things that make the web great in the first place: accessibility, cross-device publishing, responsive layouts, URIs).
Today, that sandbox solution is no longer feasible, as more and more people browse the web on phones or tablets or phablets.
While most print designers would agree it is a crime to set a text book in photoshop, the same holds true for using Quark (or Indesign) to create a website. The result is a sub-standard product, created in an inefficient sub-standard workflow.
I live equally in both worlds: the print world where creating fine art exhibition catalogues and stationary print design and the web world, creating websites for galleries, museums etc. Yet, while I should be the perfect candidate for using the web layout feature, I am very happy for Quark do stop catering for it.
Treat the web with the same respect you have for beautifully crafted books - it involves time, speciality knowledge (also an understanding that the web and the print world have fundamental differences in how you design) and the right set of tools - Quark is not one of them (and never has been).