The Workshop guidelines have been updated to better clarify the prohibition of monetized content on the workshop.
https://steamcommunity.com/sharedfiles/filedetails/?id=441378551

Mods fall under our Player Creation Guidelines . As such, Mods are not permitted to be sold or contain any sort of paywall or features provided in exchange for money.

Mod creators are generally permitted to provide donation links but not permitted to offer services or content in exchange for monetary support or otherwise incentivize donations.

We have not been actively enforcing this part of our guidelines as we attempted to find a compromise that would be helpful for mod creators that wanted to monetize their content but also safe and reliable for our players.

We considered methods to allow modders to provide methods to monetize their content. Unfortunately, we have been unable to find a path forward that we feel would work well.

With that being said. Beginning March 1st 2022, mods in violation of this rule will be removed from the workshop. Mods that currently offer content or benefits in exchange for money or donations are asked to remove these restrictions before March 1st to avoid further action.