How big a risk is that really? Exploiting the other side's inability to coordinate seems like a standard business trick these days. All they need to do is to pay attention and do some token changes to the product or ToS every now and then, disrupting any attempt of creators at organizing themselves. They can keep at it forever.
I have never found data on whether or not the YouTube legal entity is an independent thing while the add supplier is a separate entity they can happily say they make no money to take for their other legal exposures that YouTube generates. There's also the fun outcome that tomorrow YouTube is sunset the moment the creators start being properly organized because like you mention the jig would be up.
