It could be argued that it happened already with the confession, which would just means it would be a good thing, cause couple need up and down. This could also be used against NH as it never had any "down" ( granted it never had any "ups"

Also I have another question that is completely separate from the one above, that is, do u think Sakura will have to fight Karin? I mean Karin is kinda crazy, but I don't think it will happen, maybe just something I wanna see in my head lol.
Of course I think they will get back up and complete themselves. Have you seen dozens of movies where two get mad at each other by misunderstanding or liar reveal or they just act kids, only to get together again, now as lovers. Again, Sakura's confession brought the drama that no other confessions did. I mean he cliffhanger a confession, who does that? They always put in media because it was drama heavy, especially for them because of their conflicts. Every relationships need that downside moment. You get one can't stay but she feels hurt to think of not staying with him again; you get one guy thinks she's better off with another guy; you get the guy thinks he don't belong to her world, but she believes he does in her world; the list just goes on.
Well we don't know who Sakura is going to fight within the Team Taka, but I guess we have to wait and see.