It's a nice idea but I find how a company likes to describe itself can be vastly different to how it actually is.
My hope with Key Values is to:
1. Look beyond what companies say about themselves and focus on the culture and values of specific engineering teams.
2. Let job-seekers access information about engineering teams sooner (ie. before the hassles of applying, completing coding challenges, white-boarding, etc).
To your point, how interviewers describe their teams can be vastly different from how it actually is. Whether you "trust" that information or not, at least you have it sooner!