The old memory ain't what it used to be. I was pretty sure the Tomb was manned around the clock, but wasn't 100 sure. That's why I asked.
I wonder if they will ever add unknowns from the Iraq & Afghanistan conflicts? Probably not. I suspect todays modern medical technology enables remains from all those KIA to be identified.
Everyone's DNA is taken upon entry to the service now. Hell back when I was in we all had to submit to providing ours so it could be recorded. Long way around the barn to say you are right, there probably won't be anymore "unknowns". There may and unfortunately probably will always be missing but at least we will know who they are.