It could mean that Amy has done something to go against or be disloyal to a fanfic (fan fiction). Maybe she broke a trust within the fanfic community, like revealing spoilers without permission or using someone else's fanfic ideas in a wrong way.
At first, Naruto would likely be extremely shocked. He has always considered Sakura a friend and teammate, so this would be a huge blow. He might question his own judgment in trusting her.
One possible plot could be that Naruto discovers some dark secrets about Konoha's leadership. For example, he might find out that they were involved in unethical experiments in the past. This discovery could make him feel betrayed first, and then lead him to take actions that Konoha sees as betrayal, like refusing to follow orders or even teaming up with an enemy of Konoha who he believes has a more just cause.
One possibility could be a misunderstanding. Maybe Kakashi is framed for something that makes Naruto believe he has betrayed him. For example, an enemy could use a clone of Kakashi to perform a heinous act, and Naruto witnesses it without seeing the full picture.
Well, it could be that Rias betrays Issei for power. Maybe she is offered something extremely tempting, like a high - ranking position in the devil hierarchy, which makes her turn her back on Issei. It could also be that she is forced to betray him under some sort of blackmail or threat.
Maybe she's a writer or a critic. If she's a writer, she might have written something that either supported or challenged the norms in fanfic. As a critic, she could have given her views on the fanfic world, like commenting on the creativity or lack of it in fanfics.
She might run into a group of rebels. If the alternate dimension has some sort of oppressive regime, there are likely to be rebels fighting against it. Amy could get involved with their cause and help them in their struggle.
Amy Fleming and Ty are likely characters from a particular series or fandom. They could be characters who have a relationship, perhaps friends or more than friends. Without more context, it's hard to say exactly who they are in the grand scheme of things, but they must be important to the story if Amy is yelling for Ty.
The immediate effect would be a huge shock to Naruto. His trust in Tsunade would be shattered, and this could lead to a period of self - doubt for him. He might question his own judgment in trusting people.
One possible reason could be power. Maybe in the fanfic, there's a new source of power that Tsunade wants desperately and Naruto stands in her way to obtain it. So she betrays him to get to that power.