Sounds like marketing BS to me.

why would something more sinister be going on? Did you know mimosa is dirt cheap in northeast brazil? Its abundant, and it's main use is actually for firewood and for making fences, uses which are unsustainable and still done in mass scale. On the other hand, ethnobotanical suppliers use the roots which can be harvested sustainably. If mimosa rootbark was an expensive product, rare, it would make sense, but its not.

I dont know those suppliers personally, so I cant be sure of anything, but I know people that live around that area and know that there's mimosa in abundance and cheap

Ah, dont get all worked up. What they havent told you is that while mimosa burns, they climb on the roof and inhale deeeeeeeply from the chimney