No, I don't think I would quite agree. There is no explicit definition of a "hidden" status that grants special benefits. Hiding is an action you can take. I think it's possible to hide from an enemy in some situations (meaning they have to make a Perception check vs. your Stealth to see you), even though they know where you are.
I could be wrong.
Hiding, being hidden, taking the Hide action, makes your location unknown, by both making you unseen and unheard. In certain circumstances, it makes your
presence unknown, if a creature isn't already aware of you. If they are aware of you, you do it to conceal your
exact location. Even an invisible creature has to try and Hide to conceal it's current position. Those are special benefits, if not explicitly game mechanical ones.
As Mearls mentioned on twitter,
common sense can be applied. If you keep hiding and attacking from the same spot, your target is going to be more wary of that position, possibly gaining Advantage on his Perception check or Passive Perception. In those situations, your really kind of negating the main benefit of hiding, by staying in the location where you've already revealed yourself.
That's why I would rule that if you make a series of such attacks as a sniping tactic, for instance, you lose Advantage for attacking unseen once you've been spotted, if the attack requires you to reveal yourself, such as from behind total cover, unless you change your location after a successful Hide action. I would also apply Advantage to Perception against your Stealth once you have been see as well, regardless of concealment type, until you manage to change your location without being noticed.
You can still hide in the same location, which if it's only lightly obscured and you have a ability that lets you hide under those conditions, then at least you give Disadvantage to attacks against you for being unseen. If it's Heavily Obscured or Total Cover, they can't see you anyway, so the only reason to hide would be to change locations, and attack unseen from a new spot.