Social norms and laws influence each other but often it is norms that change first, then laws change.

Once a technology becomes massively useful and socially normalized, it is our legal systems that adapt around the new reality.

You can make the bet copyright laws won't change in the future but it's one you'd likely lose.

For one, laws would probably be weakened to allow/look the other way for "wanton" training with copyrighted works for one simple reason: governments are unlikely to go for strict copyright maximalism because that would permanently cripple domestic AI development.