FYI @ "dark vs light" posters:
the Dark type actually doesn't represent darkness like the opposite of light, but rather unfair and sneaky tactics etc.
It's better translation from the japanese is Evil IIRC.
So stop saying it needs a counterpart in a light type...
WARNING this is going to be a big post LOL
Considering the fact that there were no type changes (as a game mechanic) since GS 9 years ago, we can safely say there probably won't be any changes made in future generations about this.
But we can speculate what could be changed if it would be, which it won't.
IMO the existing types cover enough.
I mean...seriously wood?? C'mon.
Technicaly the whole system looks well balanced.
But aestheticaly I started to wonder why there were still types like bug in the III Generation, regardless of the existence of egg groups. Or why the flying type is still in.
Let me write about the flying type first.
Because At least this type should sound fishy to everyone.
It's not a real type! If it was, why is there absolutely no Pokemon with their primary type being Flying? Because it wouldn't make sense! It is an addition. If there is a poke with wings it'll be at least Normal/flying.... That's why flying elemental attacks are ridiculous. Peck? What's so flying about it? It's got to do with birds, but remember it's the flying type and not the bird type. Same for most other "flying" attacks. This could be fixed by either renaming it to BIRD or deleting it. What's it's purpose? To tell you what pokemon has no ground contact most of the time. Does it do it's job well?
NO! That's the problem.
If you create a Ground/Dragon pokemon, which has wings and should get an awesome ability like sanstream, you can't, because it has to get levitate. We all know that >FLY<gon flies by flapping wings - doesn't levitate through some psychic powers.
Same goes for all our fellow winged bugs who get hit by Earthquakes all the time. Beedrill/Dustox/Venomoth gets hit by Magnitude while Butterfree and others don't.
It makes limits where they don't need to exist.
Like for example There can't be a winged starter which is dragon as secondary type, because it has to have the starter ability (overgrow not levitate) and would illogically get also hit by ground moves.
I have a solution. Imagine the Info screen of a Pokemon in your party. Somewhere near the ability and Nature, there would be a square. If this square is colored, the pokemon cannot be hit by ground moves.
Next come the less odd bug and dragon types.
Think about it. How is bug or dragon an elemental type?
An water elemental attack is easy to imagine, but a dragon elemental attack?
look at this:
https://www.serebii.net/attackdex-dp/dragon.shtml
Dragonbreath
Dragon claw
Draco meteor
Dragon rush, ...rage, ...pulse, ...dance.
and Outrage, twister + DP mascots singature moves.
o__________O
String shot
pin missile
bug buzz
signal beam
twinneedle
defend order
bug attacks are also rather boring excuses, but at least they don't have all bug in their names.
If I hear of a BUG pokemon, it won't tell me "hey that means it has bug elemental powers!" but rather "it's represents a bug like living being from the real world or has bug features on it's body"
That's where Egg groups come to mind. There is a bug egg group as there is a dragon egg group. Bug/Dragon type is like fish, plant or mammal type. o_o
Would you like a mammal type? No, this just tells what kind of animal it represents which lets you know what different species pokes can breed. Even an ancient or fossil type would be more logical.
About ghost. Nothing is really wrong with it, beside it's name.
Ghost pokemon aren't real ghosts of dead pokemon. They're just strange beings. With unexplainable body structures most of the time or made of some sort of gas etc.
Why not just call it Abnormal or Strange? Or even ??? <_<
But with such changes there would be some type missing. The only type that would really make sense, but not with the current types available as it's mostly covered by flying. It would be like a sense-making flying type if created.
Wind or Air.
All this would change alot of typings, which is probably one more reason why nothing like that is going to happen.
But it would be awesome if you ask me.
Flygon could be Ground/wind
or for example some obvious choices: Altaria, Drifblim, Hoppip, Rayquaza etc...
With the flying/bug/dragon types missing, alot of pokes would get their "hidden elemental powers" "officially", like for example Dragonite being an wind/water or wind/electric pokemon? Or Crobat line which has 2 working possibilities, poison/ghost or poison/dark o_o
Many bug pokemon would probably become normal. Which if you think more about it, would actually be logical. I mean why would a catterpillar be a more special animal than a cat when neither has got any real elemental powers?
Less types would also mean easier balancing of the extremely changed type system Dx
Oh....So much about something that won't happen xD