The next DCS might be. You guys are not reading all there is to read.
The P-51D will be the first aircraft in the Flying Legends series that focuses on historical aircraft that have set benchmarks in combat aviation. This series of simulations demonstrates the broad scope of DCS simulation environment and its ability to introduce aircraft from all eras into a common simulation environment. While the P-51D started as an internal technology demonstration, it has evolved into an independent product that adds an all new dimension to the DCS universe. The development of the P-51D and other Flying Legends series aircraft definitely does not preclude the continued development of modern aircraft.
The 'Flying Legends" will be done by a new studio (no clue if they will be full games or just add-on planes.) The development of these planes will not slow down the development of any new modern combat systems. (supposedly)
So basically they are just going to be more flyable planes for DCS multiplayer. I am hoping they flesh out a Korea war simulation though when they go to release the p-51 but I have my doubts. I bet they just throw it out as an expansion that requires a-10 or bs2.