Regarding cardinal directions being used in cats' names: In the manga at the end of Tigerheart's Shadow, Berryheart mentions traveling north.
Take this as you will, as the comics sometimes use different language than the main books due to being written by a different person, Dan Jolley.
For example, in Ravenpaw's Path, Ravenpaw mentions the smell of cow poop. Throughout the rest of the series the terms "dirt" (e.g., "making dirt", "the dirtplace") and "dung" (regarding "mouse-dung", "fox-dung", and such-like expressions) are used instead.
(This also sometimes happens in the novellas, like in Ravenpaw's Farewell when Violet calls her kits "poppets".)
While this is true, directions are still not on the list of Warriors names, and that is generally what I go by rather than if it’s a word for them or not.
There is also the interesting factor you point out about the different authors— I know that during the mainline series, the Erin’s often disagree on things which creates conflicting accounts, such as I believe it was Hollyleaf being stated as having different eye colors on the same page.
There’s also the cultural difference factor. The original Erin’s were all British, and so words may be different.
TL;DR: Warriors canon is shaky at best /hj
