Doesn't the concept of what is trivial shift with what is possible with LLMs?

Doubt it. If you needed an LLM to launder it it's surely not trivial. Trivial is any well known code pattern for example.

"for(int j=0; j<ARRAY_SIZE(a); j++) total += a[j];" - you could copy paste this and more out of leaked Windows source code and it still wouldn't be a copyright violation. But beware that a sum of a large number of trivialities can be not trivial.

I would be worried about transformation via LLM being considered a "trivial transformation". Trivial transformations do not remove the original copyright.

All completely unsettled law at this point. And, as a general guiding principle, you do NOT want to be one of the people who pays millions in legal fees and court costs to find out, whether you are right or wrong.