The main cost is probably the extra workload put on their social media team having to publish to and interact with even more platforms.
While it’s nice, I also don’t think the government should spend time and money on a platform that people obviously don’t use much.
RIF did have to change their name though. https://www.reddit.com/r/redditisfun/comments/el8ri3/reddit_is_fun_is_being_renamed_to_rif_is_fun_for/