To me fediverse just means different communties being able to talk to each other.

It seems like a lot of people use fediverse as a generic term for any decentralized system.

I'm not sure. And I'm not sure there's legal precedant for that either.
That's why I dont have a problem with any of these lawsuits, it gives us clarity on the legal aspects, whichever way it goes.

If you release code under gpl, and I modify it, I'm required to release those modifications publicly under gpl as well.

It's not a fair trade if there is no consent.

A human can, within limits.

But software isn't human. AI models aren't "learning", "practicing" and "developing their own skills".

Human-made software is copying other peoples work, transforming it, letting a bunch of calculations loose on it, and mass producing similar works as the input.

Using an artists work to train an ai model and making similar stuff with it to make money off of it, is like copying someones work, putting on a mug, and selling that.
It's not using it as inspiration to improve your own skills.