Mojang java developers and C++ developers are two separate development teams, with very different code structures and methodologies. To have them work together either the C++ or Java editions would need to be rewritten, most likely the java version as it has the more dirty code. They actually did this with producing the Windows 10 version.
With Microsoft introducing paid microtransactions in the new "Together" scheme, they are looking to monetize the game as much as possible. The Java version has mods, and is still under development. Eventually, Microsoft will stop supporting Mojang in updating the Java edition, but we have a very active modding community that will continue to support MC into the future. Other game with mod authors supporting them for ages do exist and the same will happen with the Java edition of Minecraft.