Not right away and I don't have the time to search for it. Youtube is notoriously secretive about their contracts. There was a big outrage among the creators about the changes in 2017 or so.
The revenue split may have stayed the same but the revenue total has gone down, despite the huge increase in the number of ads.
E.g. Mathias Wandel has discussed the financial side of running YouTube if you want to dig deeper.
Do you have a source for that? As far as I know, the YT revenue share has been stable (at 55% to the creator) for like 15 years.