I could be wrong but I don't think YouTube TOS allows publicizing this kind of information. I would be afraid of my channel being de-monetized. I believe they have a similar policy for AdSense.
I think such policy is illegal in many countries. An employer cannot prohibit workers from discussing salaries. This is often a measure to combat against gender discrimination at a workplace. I’m not sure how this affects contractors, but I would be surprised if these laws wouldn’t cover contractors as well.
Usually a wage or salary is a payment in exchange for doing something. Which this isn’t.
I would imagine most places treat this similarly to the way something like a book publishing agreement works.