There were a ruling back in the day with similar to cut down on LRP on Xeno's hivemind and marine's constant OOC in IC along with other poor behavior. This was two or so years ago I believe when Feweh was an admin. Everyone did get the ban hammer that went against the rule for a short while before it sprawled back into a LRP cesspool.
I am skeptical of this rule that is going to be "enforced" long term. People who are xenos usually go back into lrping and marines have Delta, being "delta's" embrace the LRP side of them in order to keep up them being batshit insane. In my opinion, LRP has become apart of the CM identity which past admins/mods allowed on rounds and announcements until everyone take it too far (the shotgun loadout round).