This is literally just completely incorrect. They spawn at level 4 sentinel alert. I almost got my ass kicked by one because I stole a bunch of gravintino balls and didn't stop to right or run. There's a mod that makes them spawn at random too
well I have literally never encountered one and I've attacked like 90% of the sentinels I ever see, either way it sounds like they're barely different from the normal sentinels anyways.
the fact that you have to specifically hunt out stuff like this that turns out to be basically nothing is reason why NMS was just a loving dupe to reel us in long enough so that we couldnt back away before we realize "hey there isnt stuff in this game"
furthermore, steam support completely removed No mans sky from the support ticket selection:

thus proving even further that the game is a loving scam and steam isnt owning up to it, even though literally everywhere else is.