Welcome to the fuzzy world of social sciences my friend! More seriously, these guys need some help from other disciplines (psychology, sociology or business administration). There are so many ways this thing could go wrong... Reinventing the wheel can be a cool side project, but won't get you published anywhere.

Randomly assigned teams sounds like any straight out of college hiring pipeline, although controlled settings is harder. Google has done research on this, although I don't think they've done much with it.

Good point. I don't think Google did exactly that, but I did find this: https://hbr.org/2013/12/how-google-sold-its-engineers-on-man... It still is Google specific data though, so sadly it won't generalize as more than a set of ideas to test.

Reading what you are saying, I would say more that there is a link between unhappiness and these things. This title is borderline negligent.

I agree, the title is certainly overconfident if not negligent. Preventing people from writing inaccurate communications would be the topic of many studies and papers by itself though!