The ban on DAI is legally questionable because the DAI is not directly tied to the dollar ramp like Tether.
There is no Dai ban. They won't know or care what it is. It's irrelevant. It only lives in one microscopic corner of crypto.
This is about things like Libra. That would instantly eat the world and take many currencies with it. If you were in Venezuela would you prefer the Bolivar or Libra? It's a no brainer. That's why they won't permit it.