Do you recall which rule/law required unbundling of charges?
The most likely reason for the change in fee structures is that Patreon simply needs to charge more money.
Could also have been something contractual with the payment processors relating to fraud detection or prohibited item/services, but it seemed like it might threaten their current payment setup.
I'll see if I can find anything, but something in the firefox 56-57->52 ESR downgrade appears to have eaten all of my profile's History, and I'm not sure I can be bothered rummaging through external backups :)