SBP doesn't make the laws in Pakistan. It can only prohibit financial institutions from touching crypto. In fact the SBP's ban is unconstitutional because one of the fundamental rights we enjoy is to be able to buy anything we like as long as it's legal. If we had decent sized exchanges they could have taken the SBP to court over the ban. Instead the only exchange we had folded overnight. In India they had large exchanges which took the matter to court and the government over there has had to re-evaluate their central bank's ban.
I wish if that could happen in Pakistan.
You know if we get caught by FIA let say buying or selling crypto, we will spend rest of our life proving innocent. Of course if some big guns are there they can amend the law so until now; the documented law is silent and FIA just know one thing "Cryptocurrencies are illegal", this is the first hand information from FIA Cyber wing in Islamabad, I got it personally.
Same statement from Financial Monitoring Unit
http://www.fmu.gov.pk/virtual_currency.html