It isn't only LLMs that use rhetorical constructs like these, humans use them too.

Not to mention these patterns didn't come out of thin air. The LLMs are statistically regurgitating language from its training set, which researchers probably tuned more towards journalistic sources like the one we're reading.

Funnily enough "It isn't only X, Y too" doesn't trigger my AI-sense nearly as much as "It's not just X, it's Y". Similarly in the above quote the "It's not just U. It's not just V. It's not just X, it's Y" doesn't seem AI generated to me.