It is planning to set up a digital payments system in about a dozen countries by the first quarter of 2020
https://www.bbc.com/news/business-48383460
Sounds old, but this might be true this time.
Facebook likes to control everything - just think about WhatsApp and Instagram. The more we learn about the processing and use of our personal data by this company, the more suspicious the idea of creating their crypto becomes.
Bitcoin’s sense is to reject centralized systems and transfer control over your finances into the hands of each individual, but I doubt very much that FB supports this idea. This new crypto (if they really launch it) will be not decentralized at least.