Hey, Lightfan here. I wanted to discuss the logic of a Saint/Light type added to balance the types. Saint in Japanese, Light in English. Now, Fairy type has some moon symbolism, so it would make sense for Light to have sun symbolism.

Light would be ineffective against Grass and Ice, because those types need a defensive boost. Light would be weak against Dark, Poison and Psychic, because they need buffs. Light would be supereffective against Ghost, because it needs a debuff. Any other suggestions?

It is unlikely GameFreak will change their resistances due to their statements that the game is "perfectly balanced." GameFreak is more likely to add a new type than rebalance the existing type chart, since they already added Fairy instead of rebalancing the type chart.