Technically Facebook is still called Facebook, it’s the parent company (IE who owns everything and who is listed on the stock market) that’s now named Meta. However it’s a similar situation to Google and the parent company Alphabet, No one calls google or google connected products Alphabet products because it’s not meant to be what you refer to it as.
there is a few exceptions for this rule like self employed and individual contractors and sometimes if you work for a very small business however they are exceptions, for almost everyone else it should just be a bill that can be contested if there is issues.