Meta internally have been using Google Gemini
"Meta has been using Google’s Gemini large language model for most of its moderation and customer support, but staff have recently been told to switch to Meta’s new foundational model, Muse Spark, the people said."
https://www.ft.com/content/39251a31-4a9d-4870-b86c-dc6353d67...
It feels really insane to me that they have a model that could be better, but its just sitting there burning a hole in his wallet instead as he chases trying to recreate Grok's companion thing.