You will still be able to download and install these versions, but some features will not function as expected. If you purchased Rocket League for Mac or Linux on Steam you can download the Windows version. The macOS and Linux (SteamOS) versions will no longer be updated or supported after the final patch. Because of this, we will have a final patch for these versions in early March.
This has made it more difficult to support macOS and Linux (SteamOS). This includes adapting to use new technologies. We want Rocket League to be the best experience possible for all our players. After the next update goes out for the game, it will be the last one added to the game on those systems as they will discontinue service beyond Windows PC and console. There's a lot of Rocket League fans who are unhappy with Psyonix and Epic Games this week after the devs released important info about Mac and Linux.
