Somehow the addition of less requested animals in the packs makes me even more positive for 2023 because you can spread the highlights over more packs. But of course, if Frontier says, development of PZ2 could be more proftibale than support will stop. But I would say there is perhaps a chance that release of a sequel will be in 2025 or later. And with the Profit of a new game compared to DLC it depends how the DLCs are sold. With the current model:Why? Thats easy question. It depends how profitable according to them sequel would be.
If Frontier will decide that PZ2 with birds and aquariums will make a lot of money then they will stop support to leave some animals (dlc) for sequel. In meantime Planet Zoo still would be making money like PlanCo currently does.
Atleast there is some hope for birds for me in current game, because current dlc system works in harmful way for sequel dlc content. Unless next 3 pack would feature less requested and kinda niche animals. Think about more animals like caiman and water buffalo.
PZ (complete new game, new mechanics, some new animals, new scenery) : 50 Euro
1 year of DLCs: (22 Habitat animals + 4 exhibiti animals, 300 pieces of scenery): 40 Euro.
As long as enough people buy the packs it seems more profitable to me.