Is it possible that after WMATA receives all the new New Flyers, they will order Orion VII Next Generation hybrids or CNG's?
It depends on WMATA's relationship with Orion. Now if I am correct WMATA does its bidding process a little different than most other T/As.
We might see them get NABI CNGs if a certain someone wants to go in that direction. I won't say who :D.
Anything is possible but bus procurement is a hairy process that is not as simple as "Hey Orion, send me some buses". Lowest bidder is often the name of the game.
If you really want to see some more piece of crap Orion VIIs (sorry but they are junk), Fairfax Connector is due for some 30' NGs "this fall".
We'll I guess thing we can do is wait and see.