No what? The US's embargo and threats to tariff countries that don't match this embargo is blocking most but not all oil bound for Cuba. Russia, for example, continues to trade with Cuba because it's willing to tolerate increase in tariffs (not that Russia is trading much with the US anyway).
If this were a blockade then the US would be boarding Russian oil tankers even if they're legally flagged as a Russian vessel.
If you really think the distinction between blockade and embargo is irrelevant then we can just acknowledge that it's an embargo, not a blockade, and move on.
Ok! So the answer is in fact 'yes', with once again the rider that it is not something we should call a blockade. That seems fine with me, I think we agree about the important thing here.
If this were a blockade then the US would be boarding Russian oil tankers even if they're legally flagged as a Russian vessel.
If you really think the distinction between blockade and embargo is irrelevant then we can just acknowledge that it's an embargo, not a blockade, and move on.