There are a number of potential factors behind such a non-specific delay. The widened scope of DL2 could play a key role. The environment and gameplay can change radically based on your actions, and that's likely no small challenge to implement. Long delays like this can also signal a desire to significantly alter game mechanics. And of course, Techland and Square have to consider the timing of new consoles. Spring 2020 is just months away from the launches of both the PlayStation 5 and Xbox Series X. While there's no guarantee you'll see a fully optimized version of DL2 for those systems, it might make sense to hold off on the game until it makes better use of the new hardware.

Hey Survivors!

Here's the Dying Light 2 Development Update. pic.twitter.com/CKMkAe2eD7 — Dying Light (@DyingLightGame) January 20, 2020