It has become quite a meme that Bethesda keeps re-releasing Skyrim. The game came out in 2011 and got a remaster in 2016 and also got a port to switch sometime later. This time however it is not the same game but it is an Expansion pack for The Elder Scrolls Online.
At the first quarter of 2020 we get an huge performance update. You will need to reinstall the whole game but you get some huge performance updates. For example the game will be 30GB smaller than it is now. Faster loading times and better FPS will also be included.