Of course, data confidentiality should come first for any company. But what do we see in reality? Mobile operators sell databases, sometimes it seems that even banks spread information about the contact information of their users. If Facebook adapts cryptocurrency payments, it will only help its rating. There previously were much info that Facebook confidentiality = zero, everyone can buy user's password, what r we gonna see if they launch crypto payment?
Joining the blockchain industry still will not change the fact that they have zero rating when it comes to peoples confidentiality, which is why I do not completely trust their use of cryptocurrency too to run their business because it will be absolutely impossible for Facebook to create a decentralized coin.
This coin they are creating will be another centralized coin that will not protect peoples details or keep it anonymous, so I really dont see the need for people to accept the coin. If you see that I support Facebook coin today, Is just because I am hoping it will create awareness for people who would like to invest in BTC.