There are going to be multiple endings for the sequel
Think about it. Ness is going to be the one who decides how the new Gensokyo should be. Yukari even already hinted that there's going to be different "routes" that he could take. The choices would probably be between:
- Return Gensokyo to the way it was before Porky came (essentially pressing the Reset Button)
- Merge Gensokyo with the Outside World (not necessarily a bad choice, considering that youkai can become humans if they want to)
- Follow Yukari's plan to unite Gensokyo under her rule, ensuring that the incident would never happen again
- Jossed. The needles are mere fakes so all that stuff about creating a new Gensokyo are lies, too.