Not cutting off, but it's enough that the US increases oil supply which lowers the prices to significantly hurt Russia and Iran. And then you have China which is the main consumer of Venezuelan oil so you get another point of leverage.
Also probably helps to ensure the petro dollar is here to stay for longer.
Obviously this is a very shallow analysis, and there's definitely significant risks, but I do think it's obvious that it has large potential upsides.
It's not shallow, it is gullible. Of course Trump has an angle otherwise he wouldn't have done this. We can speculate about what the angle is but there is absolutely no way that he did this for the good of the Venezuelan population.
Edit: So, that took only 8 minutes, the other shoe just dropped, it was about the oil after all. Where do I collect my check?
In the short term this will likely decrease oil supply and drive up oil revenue for Russia.
Well... POTUS just said that the plan is to sell large amounts of Venezuelan oil to China and Russia.
So again: conceivably sure, but the details matter. The details we have right now do not look very promising IMO.