I know Apple has been very open with creating their own LLM, and Microsoft isn’t exactly hiding the fact that they are too.

The one that will be hard to squash is Gemini, since it’s fairly far along in terms of development and it’s also backed by Google. Being backed by Google is either a sign that it won’t ever die, or that it will be cut in the next 18 months and end up as another item on killedbygoogle.com