In all honesty, no. Under what circumstances does that make any sense? I'm not normally one to argue with a GM about their rules, but that one just doesn't make sense. That would immediately eliminate variation in both strategy and approach, plus there are Pokemon that would never be able to overcome a type disadvantage. For example, Staraptor VS Onix. Staraptor can learn Close Combat, which allows it to overcome the fact that it would otherwise have no moves to deal damage to the Rock type.

Again, I'm not trying to cause trouble or sound like an ass hole, but I sincerely cannot agree with that.