You gotta understand how game development works. The first year or more, it's all just engine building, scripting, defining aspects like the physics, the core mechanics, etc., and then plenty more time spent filling it up with animations, models and textures, dialogue and content, netcode, maps, item stats (which take time to balance), gamemodes, specific and generic NPCs, quests, and so on, and at this point the team probably would find some issues or limitations with the core engine, which they would have to further tweak to fix or to unlimit themselves. Then, there's still stuff like the new and improved map editor and recording mode, and all the polish that goes into each texture and asset and model to avoid weird graphical glitches or clipping. And I didn't even cover all of it. They definitely don't want to run into the issues that spin-offs like WFaS or Caribbean had, though both were made by a different studio/company. They still want to get the mechanics from those games/DLCs and popular mods that got people to buy the game in the first place.
This is why I still have faith in my #1 man.