Probably not, except as something that is expressly a gimmick, albeit it one that people can take as seriously and ambitiously as they like. I could see something like this working for a Sharlayan-themed 4.0, with some "this is your story" overtones, creating your own world inside your mind, a book, or some item of shared memories, or even just as, quite literally a practice tool or toy used by their students. It can also double as a massive improvement, quite simply, to the idea of player housing (now more broadly player environments).

Would I want to see the developer time go into that rather than mainstay additions or, better yet imo, revisions? No.
Would I want to see our community interests fixate on their forges rather than on ideas that, if actually hammered out, could possibly provide useful insights or ideas for the mainstay game's improvement and/or advancement? No.