Hello guys, since I can’t watch the movie, I kinda re-watched the two whole seasons of Haruhi without stop and kinda paid attention to endless eight ... much to my surprise I actually managed to sit through it and enjoyed it quite well … its kinda fun in a way looking for the subtle and not so subtle difference.
But, I’m not here to wax lyrical about endless eight. The focus of this post is the fact I noticed that Bamboo Rhapsody episode happened before endless eight. It was even much more noticeable if you watch season 2 alone.
Now, I believe this is a big deal since most believes that endless eight is the main reason for disappearance. Many believed that Yuki was so bored of repeating the same 2 weeks for roughly 594 years and thus wished for a world where everything is normal and she has freedom to do as she wished. I do believe that this is true, but after rewatching I believe this is not the only reason that disappearance happened.
I would even like to state that in a way disappearance is the reason for endless eight exists or at least one of the culprit.
The important clue here is Yuki synchronized with herself but only until the
Tabanata 3 years forward. After the bamboo rhapsody episode, Yuki no longer has much foreknowledge about the future except disappearance in which she knows that she’ll go astray but not the actual cause of it. Then, endless eight happened, wherein the present is stuck in a groundhog loop – time itself is not going to go forward. The S.O.S brigade cannot do anything about it since beside Yuki most of the time they are unaware that a loop is even happening and Yuki will not break the loop itself since according to her she is only here to observe.
Yuki’s reason for not breaking and telling the rest what is happening is technically true, observing Haruhi is her function, but really we already have enough evidences that Yuki does not strictly follow that. If observing is her only function then any result will be fine for her but, Yuki actively safeguards the brigade and helps ensure the best possible scenario from happening. Of course, this could be tacked on as additional duties she took on as part of her observation duties, but breaking the loop could also constitute this. If Yuki really is bored out of her mind and wants the loop to be broken she’ll do something about it and pass it to the IDTE as there are no more new data happening, thus needing some proactive action. But, Yuki despite being bored out of her mind did not do anything - meaning something is stopping her which is the knowledge of
disappearance ….
Let us put ourselves in Yuki’s shoes for a minute, we know that we will do an error in the future but is unable to stop the error from actually occurring. As time passes by, she get closer to committing the error and her foreknowledge of the future is gone. Soon, Yuki knows something will cause her to change her current mindset and make her go astray.
That is probably a very scary possibility 
and she must have been trying very hard to prevent it to no avail. And then, time began to continually loop around her, no one is actually getting hurt and the IDTE is still getting their data. Thus, Yuki allows the loop to continue with minimum interference in her part. No matter how much boredom Yuki will get from undergoing this loop, it is familiar and safe and as long that time is looping
disappearance won’t happen.
The sad thing about this is it’s because of endless eight that Yuki got those errors that caused said disappearance. Thus,
by trying to prevent disappearance from happening endless eight occurred which made disappearance happen. When you think about it, is it no wonder Yuki sealed the ability to synchronize...