The coin has already been rebranded once in 2014 (from summercoin v2 to Navajo).
Then it was forced practically to rebrand a second time because of supposed complaints by the Navajo tribe. I don't really believe it was the tribe that had a problem (or even knew about the coin in the first place), but probably a bunch of trolls. Regardless, better to be safe, they rebranded again to plain NAV.
It's the easiest way to avoid confusion as no changes are needed to be performed in the markets. Being a meaningless name is no big deal.

I suppose a backronym could be invented. Something like "Neutral Anomymous Value" has been suggested in the past.