I don't think that the issue is the quality of their QA. Well, okay, maybe that's a factor, but I don't think that that was the big one for Fallout 76.
Some of the issues in Fallout 76 that they shipped with, they had to know they were shipping with. It wasn't that QA didn't turn up problems, but that they took too-ambitious a plan, ran out of time, and then didn't delay the release to fix all the broken stuff. Yeah, they did a lot of work to fix the game post-release, but by then, a lot of players had already been soured by the initial bad experience.
They did significantly delay the Starfield release, so I assume that they are trying to put this out in a more-sane shape.