The fact is this is not a big issue, the government will not entirely banned cryptocurrency because they know what they can earn from regulating it (maybe adding tax to exchanges) and NITDA Offered scholarship on Blockchain last year November, though they can be Blockchain that doesn't have a coin but its shows they acknowledged the technology which cryptocurrency are built on.

Even if they later decided to banned cryptocurrency in Nigeria entirely, Nigeria bitcoin and crypto adoption will continue to surge and this may make us all adopt the use of DEX and non-custodian wallet.
My reason for this is from the fact that cryptocurrency is totally banned in Morocco but they are among the top countries mining cryptocurrency, while mining consumes more energy than any other sector in the country and so the Morocco's government is working on proper regulation of crypto. Also this as become many Nigerian source of living and won't just stop because the government says so in fact more adopters are coming