Crypto has been banned due to critical issues on China last time. But the stand now is different lots of authorities are favouring now crypto and this could be the reason facebook are now enetering this business. They are trying to raise 1B$ for this payment system but Im not sure if this facebook coin will be blockchain based.
crypto was banned on china , yes i believe on that but i dont think that it is the reason on why facebook also banned crypto ads . i believe that facebook has thier own reason on why they do it but now its nice to see that facebook change thier minds , now they are now allowing crypto ads which was great because this can help the adoption aswell as the price to grow more evenly