Wouldn't it end badly?
When many fans saw Chu Yu's statement, they felt a huge weight lift off their shoulders!
Although Chu Yu had never given a story a bad ending, he did have a history of abandoning them. The follow-up to Rurouni Kenshin: Trust and Betrayal, for instance, had gone silent for years. The ending of Initial D had left fans with plenty to imagine, too, and as for Natsume's Book of Friends, fans figured Chu Yu could keep it going for as long as he wanted. As for Lelouch's Third Season, all its fans could do was sigh!
You could say that many of Chu Yu's works felt abandoned to their fans, but without exception, that was a world apart from ending badly!
In the Parallel World, Hunter x Hunter had switched to a half-abandoned, once-a-year release schedule, but that hadn't affected its status as a masterpiece in fans' hearts. But if Hunter x Hunter had ended like Attack on Titan's original Parallel World version, it would have been like plummeting from the peak of Mount Everest to the Mariana Trench!
Fans weren't afraid of a story being abandoned. They were afraid of a bad ending! An abandoned story was a regret; a bad ending was a stab to the heart!
Of course, right now these fans simply thought Chu Yu had come up with a perfect ending to fill the huge hole in Attack on Titan!
They hadn't imagined that Chu Yu was doing what he'd done with Initial D: simply cutting off the later plot that would have ruined the whole thing.
But fans who interpreted Chu Yu's post that way had to be said to have reached the height of their affection for him that night!
The whole anime community spent the night talking about