I feel like that was a cool and unique enough mark for original subreddit to give it a different vibe than most other communities with similar intent.
It also helps standardizing the titling format just enough to make it less confusing and clearer when reading them. Now that there is a brand new modding team I feel like this could be a good thing to add here
i think its a solid addition. like you mentioned, it does help distinguish posts more quickly to know what sub the post belongs to. As long as its not a ton of work for the mods.