Garry Newman's post on Twitter seems to tease he's "making GMod 2", as you can see below, though it's not exactly confirmed at this stage.

The creator of the weird physics-based sandbox game Garry's Mod lowkey reveals that Garry's Mod 2 is currently in development.

Official Gmod spiritual sequel Sandbox was just made public, and the tool proved so popular that it completely broke down straight away.

There's a lot of 'is this Garry's Mod 2', the honest answer is 'maybe'—but nowhere near that yet.

The Garry's Mod comparison crystallised after realising the Teardown workshop has a straight-up GMod Physgun, letting you fling entire buildings around your head.

Players Have Flocked Back To Counter-Strike: Source Following GMod Integration Over the last few weeks, Counter-Strike: Source (and Half-Life 2) content has been added into Garry's Mod. This means ...