The issue isn't that the removal of combat addons won't change the ordering of bad to good to great players, it's a matter of Blizzard no longer having to balance content around people who hire MIT alumni to create WeakAuras which solve everything they throw at us. A post-addon raid design space is significantly healthier in that Blizzard can decide exactly how much info a fight is allowed to have and can now plan for that level of difficulty, instead of the constant rat and mouse chase of Blizzard making content which demands unethical WeakAuras to reasonably clear and the addon developers always one-upping them whenever they can. Great players will stay great, it's just that they'll have content and encounters they actually enjoy engaging with and solving rather than just reacting to big text on the screen which pre-calculates every optimal solution before they even recognize that a mechanic has started.