That's not entirely correct. You said a Ghost type is immune to "main status moves" the same way Ground type is immune to Thunder Wave. This isn't true, as Ghost types can be hit with the normal move Sing, and end up being in inflicted with Sleep, a main status. When a Pokémon is immune to a certain type, they are only immune to recieving damage from that type.
Ground types being immune to Thunder Wave is a different thing. Similar to how Grass types are immune to Leech Seed, even though Grass types aren't immune to grass. These are just example of types being immune to certain/specific moves, and is separate from a type being immune to another type.
So, Ghost can be hit with any Normal status move, but not a Normal physical or Normal special move.
Ground type having immunity to Thunder Wave is just a specific perk of being that type, (like how Ice types take no damage from Hail, and Steel types can't be poisoned, etc) not a rule