As a still pretty active player of Pokemon Go (I know guys, I'm lame) I can totally see this at play every day. Sure, the Gyms are still chock full of Vaporeons and Dragonites of lower level players, but the high level players tend to neglect them in favor of showing off their rare new Gen 2 evolutions... plus, Tyranitar, which is actually the best in the game right now.
Point being- while some players will always play completely min-max competitive (eStormies, eProbe, etc) others just want to make a good list with some chrome as a bonus. And frankly, I see that as a good thing. The fact that everyone seems to do it is a bit frustrating, but it also makes that strategy all the more viable. If it was just one person trying out the new units and he didn't do well, people would be complaining the opposite, that the new expansions aren't even worth picking up.