I think it'd make sense to have this group. Ideally the group would have +2 rights to all Social-Tools extensions. Currently each extension has two groups which have +2 rights to it (in addition to core +2'ers, of course): ShoutWiki and the respective extension-<extension name> group (e.g. extension-Comments for Comments, etc.).
I hope that one day there will be non-ShoutWiki volunteer developers working on social tools, and in such a case having this group would probably ease the administrative work a bit since you'd only need to add the user to one group instead of 10+ groups. Furthermore despite everything, many social tools still depend on each other. The template on MediaWiki.org lists extensions categorized into two groups: ones which need SocialProfile and ones which don't. But if you want to make breaking changes to e.g. Comments (which does not depend on SocialProfile), you'll likely need to update BlogPage and LinkFilter, as well as potentially PollNY.
All that being said, this isn't exactly an urgent request by any means as right now there are fewer people working on social tools than when this issue was initially ticketed.
I'm not sure why this seemingly simple request has now taken 3+ years to be completed, frankly. I'd have done this myself years ago but to the extent that I'm aware of, I don't have the relevant access rights to create these kind of groups. That being said, my comment from 2018 is still as relevant now as it was when I originally posted it, for better or for worse.