My wife played Toon Town as a kid and in-game code sharing was by far her favorite part of the entire game. It also really doesn't sound like it was patched "immediately".
This happened before I started there, but from my understanding it was patched as soon as it was discovered. It was a tricky thing to catch since it's not something that readily shows up unless you're spying on every one of the tens of thousands of client sessions, and this was before YouTube when someone would've posted a video about it for clout.
My wife played Toon Town as a kid and in-game code sharing was by far her favorite part of the entire game. It also really doesn't sound like it was patched "immediately".