I thought the platonic representation hypothesis was much more ambitious: wasn't it supposed to apply for any model across modalities (e.g. including human minds), rather than just the same model but with different modalities? I'll have to actually read the paper but I suspect there to be very strong assumptions which defeat the interesting aspects of the platonic representation hypothesis.
It's clickbait. They don't do anything like prove the platonic representation hypothesis.
They do seem to have some really interesting training efficiency improvements, though. The paper is at least worth a read.