Hmm. Okay. Two more thoughts that seem to be where confusion is arising.
(1). I am talking in the theoretical. I have no idea if any of these tools has made available a piece of music so close to another that it would set off alarm bells. IF those tools did create such a piece of music AND alarm bells were set off, if a human was behind that use of the music generated by the tool, they would not be able to use “but an AI tool generated it” as defense. An analogy: if some German band recorded an unauthorized cover of a song that was copyrighted in the US and while I was visiting Germany they sold me a copy of that song telling me it was “free to use however I wanted to”. The copyright owner wouldn’t really be able to sue the German band in the US because everything they did was in Germany (maybe the song doesn’t even have an enforceable copyright in Germany?). But if I threw the cover version in my YouTube video, the copyright holder could sue ME for using/publishing an unauthorized copy of their copyright material. Put another way, for the end user of the “royalty free” music, it doesn’t matter how it was created, it simply matters if their use qualifies as an unauthorized use of copyright material.
(2). Maybe I’m wrong, but you seem to be conflating “get sued” with some sort of YouTube action - copyright strike, demonetization, etc. Those are two different things. YouTube being willing to cave to copyright assertions where the music isn’t actually infringing on a copyright is a whole other bag of worms.