Grand Theft Auto V just had its three-year anniversary honored with a special event and login bonus. October 25th marked Batman: Arkham Origins's third anniversary, but WB Games is celebrating the milestone a tad differently than Rockstar — with a server closure.
A WB Games employee posted the announcement on the official Batman Arkham forums:
As is often the case with online service discontinuations, it can be hard to tell which features use dedicated servers versus peer-to-peer servers, or if private matches will still be available. As a result, it is difficult to predict which achievements will be affected. For example, chat lobbies in Mortal Kombat vs DC Universe were disabled years ago, discontinuing two achievements, but other forms of online play (such as ranked and player matches) are still available to this day.
As of December 4, 2016, the online services portion of Batman: Arkham Origins
will be retired. We thank those that have joined us to battle over the last 3 years. The Single player campaign may still be played and enjoyed offline. For any questions relating to Batman: Arkham Origins, please contact WB Games customer service http://support.wbgames.com/
Our system has flagged 11 achievements that require online multiplayer; these would be the ones of which to be wary:
The Clutch achievement in Batman: Arkham Origins worth 56 pointsKill a Hero to bring back your entire gang when at 0 reinforcements on a full multiplayer server
All of the multiplayer achievements are already quite rare with none earned by more than 9% of players. The rarity will only increase if they officially become unavailable.
If you're looking for like-minded gamers who are trying to clean up this set of achievements before the multiplayer functionality is lost, the Gaming Session Calendar is a great place to get started by either joining an open session or creating one of your own.
With regard to the closure, be sure to exercise caution as there is always a chance that the servers will become inaccessible earlier than the scheduled date depending on your timezone. According to WB's post, the online services will be retired as of December 4th. Although there is always a chance that the features needed to obtain every achievement might still be alive and well, most completionists would rather not take that chance.
We've got the full list of Batman: Arkham Origins achievements - check the list for guides to unlocking them.