You're right that the "Is not" and "Will not" forms are unnatural - I suspect they are even ungrammatical in current English.
Normally, in current English, unless you're using contractions, the auxiliary (or "be" or sometimes "have") inverts with the subject, and a "not" comes after:
Do you not see?
Is he not coming?
Will they not expect you?
These forms are somewhat formal, but not unusual. In ordinary speech "Don't you see?", "Isn't he coming?" and "Won't they expect you?" are more natural.
But the forms with "not" staying with the auxiliary and going before the subject are very unusual now, though they were more common a couple of centuries ago:
? Will not he ask?
I don't recommend using this form ever.
The difficulty when you use an indefinite such as "anybody" is that the form with "not" after it is ambiguous:
Will anybody not come?
usually means "Is there anybody who will not come?" and not "Will nobody come?"
So normally, if you want to expand contractions such as "won't" with an indefinite (involving "any"), the normal choice is to use the negative indefinite ("nobody" and the like):
Is nobody coming to class?