They will definitely work, but it might be that they need to have their shadows recomputed.
If that happens, you don't need to load every single track into the editor. You can batch process all your local tracks from a command line window:
ManiaPlanet.exe /computeallshadows /user /LmQuality=Default
This worked in the early beta stages and I see no reason why it would not work once the game has been released.