The only way I could see Pokemon Go surviving is Niantic goes bankrupt and Nintendo/Pokemon Co. buys that whole segment of Niantic that is Pokemon Go, staff and all. I'm sure Niantic is paying a hefty licensing fee to Nintendo but PGO still makes a ton of money and strengthens Pokemon's brand. Pokemon GO Fest is coming back and would sell out previously. They could just say fuck it though and make another one to try and recapture the feverish audience.