This genre of games just doesn't suit mutli-player. And you cannot bang into the ancient engine good multi-player concepts.
I do have to write one thing on what you put up here. The amount of detail poured into the previous RPGs from Beth is what makes the multiplayer aspect so different, and ill-suited. Happened with the ESO push-back, it's happening here. Too many players, not enough content. The 'multiplayer' the seeming majority of people want is the same RPG content, but with the ability to play with maybe a handful of people at most. Co-op gameplay restricted to people you want to play it with, or just yourself.
From what I've gathered, the vast majority of people are looking for content like that, not what's being presented. If Beth really wanted to make cash off of every game they've released prior, then they've already taken the first step. With their launcher, if they just released 'Creation Engine: Ultimate' or something like that, in which it would be a blank engine able to load up co-op gameplay of previous games (ESMs or what-not), but only if they were re-purchased through their launcher. At that point, they could maximize the money they'd ever get from this multiplayer aspect, and their previous games all at once. Instead, they've probably doomed any hope of multiplayer success (co-op or otherwise) out of Beth due to ESO and now 76's various issues.