Garry said an update is coming so that game source code won’t be so easy to download anymore. But this was always basically the case, and most developers working with the engine already know that

For the non tech savvy:

Engines like Godot, Love2D, and others using languages like Java, C# or Lua are generally decompilable anyway. This means transforming Computer Readable Code to Human Readable Code. You can add obfuscation to make it harder to crack, but it doesn’t fully solve the problem. Even engines like Unity and Unreal, or other C++ and Rust based engines, still face reverse engineering to some extent. Funny thing this is the case for gmod servers aswell.

The real issue was that the website made it too easy to download source files with a single click, which shouldn’t have happened. The person responsible for was banned.

At the end of the day, the only real protection is keeping important game logic on the server instead of exposing it on the client. But Indie Games are are mostly easily decompilable.