The Facebook you use keeps the same logo, but the Facebook that owns it is changing.
Facebook has announced a new logo, but you won’t see it very often. The new logo will be used for Facebook as the company that owns the eponymous social network, Instagram, WhatsApp Oculus and more – the app/site will primarily use the current branding.
“We started being clearer about the products and services that are part of Facebook years ago, adding a company endorsement to products like Oculus, Workplace and Portal,” says Antonio Lucio, Facebooks’s chief marketing officer in a blog post. “And in June we began including “from Facebook” within all our apps. Over the coming weeks, we will start using the new brand within our products and marketing materials, including a new company website.
So you’re more likely to see the new Facebook logo on Instagram than Facebook itself.
https://www.digitalartsonline.co.uk/news/graphic-design/facebook-has-new-logo/