The last I checked, making maps in Flashpoint Campaigns required 3rd party software for generating hex maps, etc. There was some mention from the devs that this could only be changed by a change in system.
Will that be in place with Germany Reforged, or will there be any extensive changes to the editor?
The map values editor in the game has not changed. May have had a bug fix, can't remember. Map images are still 3rd party based on the original release and Map Making Mod Guide. William brought much better looking maps to the game, but he also uses a number of 3rd party tools to create them.