OK, so I fully appreciate that this may be an odd entry to include in a list specifically about not wanting a survival RPG version of the franchise, but it absolutely deserves a place here.
Yes, DUST is, in fact, a survival rendition of Fallout: New Vegas. There are some key differences here, though, from what you can expect to get from Bethesda, and a few reasons why DUST might be more worth your time. First and foremost is the difficulty. DUST is unforgiving in the extreme, to a level we can be nearly certain Fallout 76 won't feature.
DUST also includes something a bit different from the standard survival formula: insanity. Killing people, eating rotting flesh, and taking drugs for an edge in combat all take their toll, making this somewhat of a Darkest Dungeon-like take on the series, with a dash of Don't Starve. If you want to be challenged in a very different way from the base game, DUST is worth at least checking out.
Wondering just what Fallout 76 might look like and want to try out something similar ahead of time? You've got your answer right here, although in what is probably going to be a harder, darker rendition. For another take on this idea, be sure to also check out the Obscurum - Pandemic survival mod.