Yes, they should. I have mostly been playing old maps I made with the previous version of GalaxyForge and they work fine. I suspect all the maps you find will be made with that version.

If you feel motivated, might try messing with the new version of GalaxyForge or Map Designer. Both are pretty powerful and simple to use, giving you varying degrees of control. Not sure if you are wanting variety or want to be a cheapo like me and play some asymmetrical maps; GalaxyForge would be your best bet for the latter.