Nope, you can make units via LUA (but after the script is run, the units should appear on the OE)...
Deprotection only made it openable on the WE but the data is still "missing" (they're still there, on the map mpq, but on a file type unreadable by the WE)... and that's why the map is still playable because the protection just removed the association of the data from the WE...
you can try to use an mpq browser to open the map and find the object data file but I think it would be on the form of SLK tables...