This isn't an official statement from facebook. Yes, it's their firm in Switzerland but it doesn't mean that it's the rumor that they are going in for the stable coin. We have not seen any announcement from facebook about this kind of matter.
A kind of report, a rumor, we still don't have validation. We can misunderstood that it's part of their expansion, I have read the article and searched for other related articles and majority of them says that facebook should public it already to break the rumors.
This could just be another type of their marketing. Spread as many rumor or teaser so the public will remain engaged and talk about them every now and then. They need to stay relevant in this fast changing crypto market.
They want the attention of the public focused on what they are
developing. As crypto is on trend now, they are riding the hype but if its a real project and development for their stable coin, crypto will also get the attention from their users.
Why people like this kind of rumor/news is because it's a big company. And while we're waiting for their announcement, a lot of articles are coming out to attract more excited people about them.