The short answer is no.
Pokemon was one of the first games I remember beating, so I have a lot of nostalgia surrounding the series. It was that nostalgia that pushed me to play every Pokemon game up until Black and White. By that time, as a longtime fan, the series had become stale. While most games were evolving, or at least attempting to, it seemed Pokemon was going to stick to their original formula forever.
When Pokemon X and Y were released, it felt like Nintendo was finally ready to take some risks with the franchise. They introduced mega-evolution, new ways to connect with your friends and other players, and several other features. While none of these features completely changed the way people played Pokemon, it added just enough to keep people interested.
Pokemon Sun and Moon are continuing this trend.
From what we’ve seen, Sun and Moon are going to keep some of the features people loved and experiment with even more, like Z -moves and Alolan forms of existing Pokemon. In an ever-changing industry like gaming, products have to change to adapt to the desires and interests of the consumer. Pokemon is doing just that. The core game hasn’t changed; there’s just a few more embellishments to draw in new audiences and keep the old one interested and involved.
I honestly feel the changes are only going to enhance the gameplay. Pokemon will be forever hold a special place in my heart and I am thoroughly looking forward to playing Sun and Moon in November.