Facebook probably wants to be engaged in the advertising of new crypto projects!))) So they block different ads.)) In any case, the crypto world will not suffer from the bans on facebook!
Facebook does only following some restrictions on a certain country with cryptocurrency. A certain government may request regarding on banning cryptocurrency ads on the facebook specifically on their country but it does not mean that it will going to ban all cryptocurrency ads on other countries for this may not apply on them. The lifting of ban will also depend on the government's decision to accept cryptocurrency or not.
This was a good step from their side, cryptocurencies are being more and more popular now and ignoring them or muting them won't bring you anything positive.
If the government already acknowledge the cryptocurrency then basically it is a good indicator that will encourage people in that certain country to join cryptocurrency.