Link below...
In short, they follow Apple/Google model. Consumer devices, likely in works... Quote:
Facebook Inc. is building a team to design its own semiconductors, adding to a trend among technology companies to supply themselves and lower their dependence on chipmakers such as Intel Corp. and Qualcomm Inc., according to job listings and people familiar with the matter.
The social media company is seeking to hire a manager to build an “end-to-end SoC/ASIC, firmware and driver development organization,” according to a job listing on its corporate website, indicating the effort is still in its early stages.
https://www.bloomberg.com/news/articles/2018-04-18/facebook-is-forming-a-team-to-design-its-own-chips