You contradict yourself, or perhaps are more interested in picayune details than what tastes good.
Doesn’t gravy always have shallots (shalLOTS, as Gordon Ramsey would say) and mushrooms?
Here in Michigan we don’t fuss much about nomenclature or other small stuff. We just want to eat what tastes good.
A basic brown gravy starts with a roue, to which is added pan dripping and/or beef stock. Then, depending upon what kind of beef gravy one is making, other ingredients are added. :-)
For instance, mushroom gravy doesn't usually contain any onions, OF ANY KIND, in it.
Onion gravy contains NO mushrooms and NO shallots; but does contain "sweet" onions finely chopped and sometimes parsley!
Both can contain wine, or not any at all.
The variations are many.