The whole point of the Discovery is that it was an F-Line camera with most of the features of that line. Arca-Swiss is a modular system, and there was nothing "special" about the Discovery parts. For the same reason, Arca-Swiss could easily produce a 141mm Discovery. But apparently, they aren't going to.
The Discovery brought a lot of people to large format and to Arca-Swiss in particular. This amounts to a rejection of that marketing strategy. The question is, why the rejection? I can think of possible reasons, but my question is whether anyone knows the actual reason.