Basically, concern trolling is faking or expressing concern and sorrow over something for social good boy points, or alternatively to purposefully derail and sow discord in the community.

It's quite a slimy tactic sometimes because it can cause ACTUAL people with legitimate concerns/questions/disagreements to be labelled concern trolls if the targeted community catches on, HOWEVER, in this case, I think concern trolling may be warranted since reddit is already a censored shithole full of paranoid jannies, so adding to their schizoid paranoia isn't really much of a detriment.