The Pop Growth Changes are coming in the free update alongside the, yet unannounced, project. Our hope is to, through these changes brought to us by the dev diary, glean some information that may point us in the direction of just what that is.
In the next update to Stellaris: Console Edition, biological pop growth will follow a curve based on the number of pops on the planet, and the theoretical Carrying Capacity of the planet the pop is growing on, say the developers.
Apparently, said Carrying Capacity will be determined by the total amount of free housing on the planet, as well as the number of unbuilt and unblocked districts on the planet.
As such, the amount of Pop Growth required to create a new pop is now increased by the total number of pops in the empire. This value can be adjusted to your preference during Galaxy Setup. Though, developers warn that increasing the number of pops in the galaxy may have a negative effect on the game's performance.
The overall objective is to reduce the total number of pops in the galaxy but to keep the production more or less the same as in the previous version.
To this end, the number of jobs per building tier has been adjusted to follow a 2/4/6 progression as buildings are upgraded, as opposed to the old 2/5/8 progression, while the base output of these jobs has been increased.
In addition, pop requirements for upgrading Capital buildings have been reduced to 10/25/50 from 10/40/80.