My entire comment history is filled with criticism of capitalism, and I have a bunch of issues with proton, but this is just sad and not something I care about.
They are testing what price point is most attractive for NEW customers on a 24 month intro offer. Both of these offers revert to the standard price after 24 months.
Windscribe, as a 5 eyes based VPN, is not trustworthy, and posting "gotchas" like this makes them even more suspect. Proton is one of the only providers that offer a permanently free VPN. Windscribe has no free option.
Personally, I think a moral company would offer permanent discounts to long term customers, but there isn't a single company on earth I'm aware of that actually does that.