If it comes down to deciding between right now breaking ground on a SLoP or Pokemon attraction, it will be SLoP. They own the rights so they don't have to pay the same licensing fees as they would for Pokemon, plus they'll get a cut of merchandise sold as well instead of paying licensing fees for that. Also, SLoP is something they are interested in turning into a franchise so it makes sense to cross promote in both (or all) parks.
The Pokemon thing is big RIGHT NOW, but in a few weeks it will all go back to its past status as beloved childhood memory that became over saturated in the cultural zeitgeist. Makes much more sense to save it to be part of a new park/area than rush into something for IoA.
SLoP will continue to grow for months and years to come as kids watch it over and over again in the back of minivans and while sitting in restaurants waiting for food.