Let's all remember that whatever crazy idea you can come up with, you can be sure the military has done research on it. A big part of their job is making sure they try EVERYTHING and test whether or not it's going to be the next big thing.
The US have as recently as 2013 being paying people to research and built prototype SURVEILLANCE BLIMPS... (no, not RC-sized... full on, 90m long blimps).
Therefore I think it's reasonable to assume that anything we can come up with has probably been investigated and if there's even a hint of feasibility in it, prototyped and tested.
That's not a conspiracy theory, that's simply saying the military is doing what its supposed to be doing.
Given that Stealth technology is a proven concept and that a good chunk of its power comes from having the enemy be unaware of your current capabilities*, it seems reasonable that they'd have tried 'stealth-if-ying' everything they could.
*Stealth planes aren't all that 'invisible'. They're mostly just 'hard-to-see' enough that the enemies current AA systems (be it people or machines) will filter them out as 'noise'.
If the enemy is aware of your stealth aircraft, it gets a lot less stealthy because they'll be paying extra attention to previously ignored radar contacts.
The Nighthawk that got shot down only got shot down because the people on the ground KNEW they were being attacked by nighthawks and were specifically looking for them - they modified their radars and looked out for the tiny signature created when opening the bomb doors.
Therefore, while I'd personally love to see what the new stealth choppers look like and how good they are, I can totally understand the requirement to keep their existence as secret as possible.
I'm guessing while everybody else was celebrating the bin Laden raid, there were quite a few people in the military that saw that day as one gigantic failure, since all their enemies, even those without extensive espionage capabilities, are now very much aware of the existence of these choppers. Combine this with the ridiculous amount of relatively high-tech equipment that ISIS has managed to get their hands on and we're in a situation where service men and women relying on these stealth choppers for their survival are now at an increased risk