No. It gets people excited, active, and social. There's many reasons why pokemon go will be popular at least to me. 1) updates- updates will improve the game and may even add new pokemon and trading. 2) competitive - everyone wants to be the best. 3) completionist- completing the pokedex and achievement medals can be goals to keep people in game. 4) not pay to win.
Just like every other mobile game, this one will eventually die. Not saying that its a bad game (I haven't played it myself, but that's because I like to be different) and it probably is a fun game, but I just don't see it living past a few months. People thought flappy bird, candy crush, or angry birds were going to stay forever, and look what happened to them?
Obviously a fad for the casuals who are playing right now because they just want to be part of this phenomenon everyone is talking about. They will be the first to go and I don't expect it to take very long for a large portion of them to quit before the end of summer.
Then I can see another large portion of the player base quitting in the northern climates once the weather gets cold. Not many will be out in freezing weather or with snow on the ground doing what they are doing now. I think this game will be near dead in cold climates by the end of winter. I thinks it's why this game was released so buggy with hardly any extra features. They knew the middle of summer was the absolute best time to release this so instead of waiting they basically release a beta as the full release. No way this game would have blown up like this in colder weather.
Don't doubt the power of marketing! We're talking about Pokémon here. When the winter comes, they simply won't be outside in the snow. They'll be DASHING through it. ?? Dashing through the snow ?? Playing Pokémon Go ! ??
They are definitely going to add more Pokemon. The 7th generation of Pokemon are going to be released very soon, so they will probably add the 2nd generation of Pokemon to Pokemon Go later.
I don't think it's all about nostalgia, because you have non-Pokemon fans playing the game. People won't get nostalgia from this game because it is new. They get nostalgia from playing Red/Blue or for me, Gold/Silver.