to any subject matter? No just the subject matter they claim rights to made explicit in The Company will own (a) any inventions...

To the extent any of the foregoing is not deemed to be a work made for hire, Employee hereby irrevocably assigns all copyrights, This part just says that if what you do in your free time doesn't already transfer to them by work for hire laws that you will explicitly grant it to them.

Note: I am not a lawyer.