As far as I can see there hasn't been anything said by Michael Brookes to confirm that they are "blue zone" POIs... If the Anaconda crash site is considered a Permanent POI and it doesn't show as a blue zone then it seems like there is still some ambiguity there.
No, MB has not told us how the game works directly, we just have use the tools available.
However, you have the radar in your ship, where you know you can pick up zones from a decent altitude.
MB has said specifically that some 'barnacles' are random while others have been placed.
Regardless, we're looking for
anything out of the ordinary. That may be Meta-alloys.
Any of these may exist within or without a blue zone on your radar.
But you never know, so preferably you should check both. Zones and things appearing without a zone.
Perhaps you'll spot a persistent type9 or Anaconda wreck. I know many are looking for these as well.