https://www.gamespot.com/articles/rage-2-doesnt-use-idtech-but-the-just-cause-engine/1100-6459110/

We've learned a little more about Bethesda's upcoming shooter sequel Rage 2, which is a joint development from id Software and Just Cause studio Avalanche Studios. Someone asked Avalanche boss Christofer Sundberg on Twitter what engine the game will use, and Sundberg responded by confirming it's Avalanche's internal engine that is under the hood.

This was surprising to some, given that the first Rage ran on id Software's own idTech engine. Someone else on Twitter asked Sundberg if Rage 2 would use a combination of Avalanche's engine and the next evolution of idTech, but he did not respond to this.