Lets be careful when we talk about retaining walls for pools though, sure, it's correct that you can put a pool on a retaining wall BUT it has to be done right. One can't just haul in a bunch of dirt and build up one side and then put the pool on it. An AGP has tremendous weight and a retaining wall has to be built properly!!
There's no dispute that if an AGP is put on top of an improperly built retaining wall that this is a dangerous situation, for the owner an their family/property as well as the families adjacent.
Your pool and deck looks awesome, if people PM you regarding the retaining wall please include that they have to be built properly to withstand the weight of the pool.