The key here is certainty.

They claim that everyone would have otherwise paid for a subscription to watch it legaly. But that is simply not true.

When you could buy either variation of pasta in the store, where there is hundreds of boxes stapled, so price and availability are certain, you can speak of opportunity costs.

But here the elasticity is extreme. Many people will not buy this if it costs anything at all. Most probably would, if there is one service with reasonable prices where they can watch everyting. Some people are probably not able to watch a legal stream at all, because it isnt licenced to their country.