Memorising isn't the issue. It's providing it back verbatim and/or cutting access to the source.
You'd get the same problem with someone with a photographic memory who a group of people would turn to recite them the news instead of buying the newspaper.
As of now public performance of copyrighted material is infringement.
That's not the case, as they aren't trying to get a ruling on the forced reproduction by prompt as infringement, but rather to get a ruling that training is infringement.
I fully agree with the perspective that infringement in usage needs to be limited even if I strongly disagree that training is infringement.
