Do they win? Did the porn usage actually decrease? I'm not sure how you'd even measure that given common distribution areas like Reddit or Twitter. Unless someone does real research on this in a few months, I don't think anyone can be said to "win" here.

Short-term I would expect the usage to be registered as higher while people interested in porn are now checking other sites to figure out what's available.

Pornography is prohibited by Islam, and yet Islamic countries are among the largest consumers of pornography in the world. Humans need an outlet for sexual urges, and sexual repression only makes those urges more acute.