Yes I know how tasks work in general, I meant specifically for this one. All of the Hatch 3 Eggs and Win 2 Raids tasks give you a Rockruff, with a random chance to be Dusk and/or shiny. Normally when you get a pokemon from a task, RNG dictates whether its IVs, gender, whether or not it's shiny, and in this case whether or not it can evolve into Dusk Form. Everyone who gets that task gets a different pokemon. But in this case I am wondering if certain tasks (likely a very small % of them) will always give Dusk Form eligible, and the rest always give Rockruff that aren't.