They should be.
No, they shouldn't. In the short sense.
Point on fact. National security concerns.
Merely my opinion. All or any weapons systems developed of interest to the U.S. military should have some type of security. That includes any Congressional committees that include a Defense appropriation for funding.
I am in no way an expert in this matter. But, again, I approve of nondisclosure of certain use, adaptation, or development of what I would deem as advantageous to our military.
In short layman's terms (me) anything that could or would prevent U.S. citizens from being sent home in body bags meets with my approval.
Long term denial, such as our secret underground submarine bases in F ghanistan, being the only reason we are still there, does not meet with my approval.