Do we want to explicitly mention WMF/Wikipedia?
I say yes. We should have more general objects as well, but I think we should actually mention our real objective somewhere in there.
Do we want to explicitly mention educational goals? Outside this country?
Definitely, advancement of education is what makes us charitable. Everything needs to be worded as in some way advancing education (or possibly heritage).
Do we want to explicitly mention advocacy?
Probably not, that doesn't sound particularly charitable. If we have objects about making lots of free educational content that's enough to justify us advocating free content.