Those are two very different issues. Steamboat Willie belongs in the public domain as it's copyright has long been expired. Disney has done some shady shit to keep control over their copywritten material for far too long. It's good they backed down over that bullshit.
US Copyright law says their work only goes into the public domain 70 years after the creator's death. Carlin passed away in 2008.I'm bad at math, but uhh...it hasn't been 70 years yet... right? Or did we all go through a time warp again?
This is just yet another example as to why AI companies need to pay for the data they collect. The artwork and written work displayed on the web still falls under copyright law and thusly the works can only be utilized with express consent from the creators. And yes, until it falls into the public domain.
Now, you could argue that 70 years is too long for copyright to expire. I am open to such an argument. But that simply isnt the case right now for Carlin's work. Thusly, the creator of this ”work” should indeed be sued (rather brutally imo).
Lastly, even if all this was legal, it's in incredibly poor taste to do this. It's one thing for a comic to take inspiration from Carlin, but it would be in poor taste for that same comic to steal his work. This is in even poorer taste from what I see. What a fucking sack of shit this creator is. I hope he dies slowly from sepsis.