Myself and a lot of musicians I've worked with tend to call most non-pitched, rhythmic embellishments "ghost notes" whether they are softer or accented.
Some people may call these louder, non-pitched notes "Muted" notes.
But when I think of ghost notes or "ghosting" as a guitar or any pitched-instrument technique, it's practical application is for rhythmic embellishment which can include accented notes or unaccented notes.
Again, I am not disagreeing with any of you. I am just stating what the general consensus is of the pro musicians that I work with. I have played professionally for 20+ years, so I have worked with many.
I want to clarify that I'm not saying that "pro" players or myself know everything. There are great AND poor pro players just the same as amateur players. I am just giving my 2 cents and the niche of the music world that I come from.