All of Meta's messaging platforms are down.

This includes Facebook Business Suite. Many businesses cannot operate right now.

You can still say "Facebook". I still say "Google" instead of Alphabet.

But yea, was just about to message a friend and found this.

Quite the opposite, I'd argue that the rename makes talking about those issues easier.

Saying "Facebook's chats are down" has you thinking the chats of the website called Facebook are down.

While it's the entire parent company's services that are down. So Facebook by Meta, Instagram by Meta, etc. :)

FB, Instagram, Messenger, WhatsApp are all down globally.

Is this due to the transition of Meta?

It’s very unlikely that the name change will require any substantial technical changes within Facebook. I can’t imagine renaming configuration files, services, and so on just to reflect the parent company’s name changing. This is just making work.

seems to work for me. is it messaging?

Some appear to be coming back up for some people, but Twitter confirms this was widespread across all apps at one point.