The difference between these things and something like a "Responsible Innovation Team" is that the goals of the latter are often poorly defined and amorphous. What does "Responsible Innovation" really even mean? But contrast that with, for example, security goals, which are primarily "don't get breached". Security folks, privacy folks and accessibility folks should all have a very well-defined job to do. For the other "PR-focused" teams, they usually have to make work up to justify their jobs.
Note that, obviously, it's also possible to have bad security people, for example, who only see their job as to throw up roadblocks and demand that your security checklist is ever-growing. I'd even say these are the majority of "security" people. But the good security people who are able to integrate themselves successfully into your product development processes are worth their weight in gold.