Right now, park pass reservations are a tossup on which sells out first, but they're only selling out a few days to up to 10 days in advance. Looking at park hopper availability, only today has 1 park that you can't start at. I'd definitely plan to start a day or two at DCA, just to try to do rsr without a long wait, plus getting an early attempt at WS would be good.
But yes, you can try for either RotR or WS at noon, as long as you're not currently holding a boarding pass for 1.
For example, you get a RotR boarding group at 7, but at noon, your group has not been called, you would not be able to get a WS boarding pass. However, if you did get a RotR pass at 7 and have rode the ride, you would be eligible at noon to get a WS. Also, If you missed out altogether at 7am, you could try for either ride at noon.
There is no morning magic right now. I would not assume anything that hasn't started happening yet will be available when you go. Some things will be brought back quickly, while other things are being help off for a long period of time. So basically, until something has been announced, assume you won't have access to it.