It would be nice if people would differentiate between Facebook (the social network, a specific application) and Meta (a company that owns the aforementioned application and many others).

There is a useful tell here when someone uses the old name for the wrong purpose, it can be a flag that the person is possibly operating under old information. Anyways, if you want to remove all ambiguity and also signal that you know and aren't falling for the rebrand as reputation washing, just mention them both: Meta nee Facebook, Bayer nee Monsanto