In January of this year, new developers cfx.re (who were bought by Rockstar Games to improve FiveM and RedM) are now working on some kind of community platform, most likely codenamed SixM.
The Rockstar Careers website states that new developers must:
Contribute to the design and architecture of new features and improvements for the modding platform.
There are also a few more interesting statements about the future platform:
- Creating fully customized dedicated servers where creators can develop their own game modes and other modifications in various scripting languages.
- We create technology, tools, and solutions to improve the creator experience and empower our community to create and share every experience imaginable.
Also, the famous Tez2 insider said on the GTAForums that Rockstar could follow the path of Bethesda or go through their own path.
So far, there are no official statements about what the Creator platform will be about, neither from the cfx.re team nor from Rockstar Games, but most likely we will receive official modding support for the SixM/Creator platform with possible tools.