Probably not happening, since private and unlisted videos have plenty of non Patreon uses as well.

For example, some people use unlisted videos in thei Ycombinator or startup accelerator applications. Or on pages on their own sites where the video merely compliments the content and is useless on its own.

Removing that sort of thing seems illogical.

Another example is you only need to be 13 to have a youtube account and the interesting privacy compromise at school is the kids upload their video presentation homework to youtube as private videos.

Another example is prepping for launch day, upload and test everything then change private to public on the big day.

I suspect google can't monetize private videos because it would bring an uncomfortable discussion about income inequality at youtube (much like patreon, almost all users make essentially no money, which is not going to help content provider recruitment if it becomes noticed in wider public eye)

I can't imagine that they would do that. At the very least if they did, they would gate it for a few $$/mo. Make it a feature for red users only or something.