I haven't been in Venezuela since 02006 so I don't know how people there cash out of Bitcoin. I'm guessing nobody has a clear view of the whole system, since being transparent to Maduro's thugs is not in the interest of any of the participants. If I had to guess, I'd guess that Venezuelans who are fleeing the country sell their dollars for Bitcoin, and Venezuelans whose family is abroad buy them.

One thing I do know is that a lot of overseas Venezuelans whose remittances are via Bitcoin don't know Bitcoin is involved. They know a storefront where people transmit money to Venezuela, and the guy there tells them where to instruct their family members in Venezuela to pick up the money. How the agent in Venezuela gets paid is no concern of the customers; they only care that the money they give the guy arrives safe and sound.