Quote:

so are the pairs similar to an oxymoron then Wofa

what about these...

not yet
not always
not ever

Not exactly. The oxymoron is a self-contained opposite -- "jumbo shrimp."
These false opposites have the external appearance of opposites, but rather instead they are like two lines that don't even intersect, rather than going in the other direction.

full duplex (teletype transmission in both directions at the same time)
empty duplex (can't rent my apartment for love nor money)

Your other examples are negation rather than contradiction .