No one here can say when the next PhotoLab will be released. But we can infer based on when previous versions were released.
PL1 - Oct. 25, 2017
PL2 - Oct. 24, 2018 I think
PL3 - Oct. 25, 2019
PL4 - Oct. 21, 2020
PL5 - Oct. 20, 2021
These dates are all available through an Internet search for press releases by DxO.