It would seem that Gears of War 2: Ultimate Edition is not being worked on as of the end of 2018. This would be a remaster of the second entry in the series following a similar design to that of the updated effort on Xbox One for the original Gears of War. During the latest developer livestream (Twitch) on October 25, 2018 there were multiple inquiries as to whether this game was being worked on. The devs were very confident in reply to mention that they are far too busy with three games in development including Gears 5, as well as Gears of War 4 support to be working on that.
They didn't necessarily rule it out for the future, but clearly stated they don't have the resources available to possibly be working on it. The time stamp was at 1:22:00 which can be viewed from the link to the video below. For context, Ultimate Edition was a fresh remaster of the original game enhancing visuals, the multiplayer and then bundling it into a seamless package for players on Xbox One to enjoy. You can find more Gears of War coverage in our hub below and read about the Gears 2 Xbox One X enhanced preview below.
Twitch Stream Mentioned
Read our Gears of War 2 Xbox One X Preview
View our Gears of War Hub