Neither wine nor xterm have virtualized cpu or memory, they both imitate (= emulate) some system via their interfaces, yet one is primarily an emulator and the other is not one. That does not make sense.

The wine project changed name to avoid the bad reputation emulators had back then due to their poor performance. "Wine is not an emulator" is not factually accurate, its a social workaround.

Words can have different meanings in different contexts. "Wine is not an emulator" was a very useful tagline to indicate that it was fast, as opposed to virtual machines like Virtual PC, PCTask etc.

"My bicycle is not a vehicle because it doesn't have a engine"

Actually "Wine is not an emulator" is factually correct.

Wine is a re-implementation of win32 on top of (near) POSIX OSes like Linux.

Then xterm isn't an emulator either, its a re-implementation of the DEC VT terminal protocol on top of a POSIX-like OS. Pick one.