I can certainly understand why some people don't want Kotori to actually leave. Yes, it would take away from Nozomi's 9-person conception of Muse. And yes, it is a sadder ending for Honoka and Kotori, and would leave us wondering if Kotori would even be in a sequel to Love Live!
However, my view is this - The writers made a bold and hard choice in this episode. But in fairness to Midonin and some others, whether that's the best choice
is up to debate.
The writers could have given us a clean comeback story where Muse continues on its magical flight to Love Live!, and
dreams become
reality after a lot of hard work, sweat, and tears. For pure "fun factor" and simply making the audience smile, I don't think this could have been topped. But the writers decided to go in a different direction.
The different direction they went in is less happy, less magical, less fantasy-esque. The show becomes a bit edgier, a bit weightier, and a bit more "real", but we shouldn't downplay the trade-off it makes to achieve that. Love Live! isn't as "fun and happy" now as it could have been.
Now, if the writers follow-through on this edgier, realism shift, then at least the shift achieves what it was meant to. But if the writers do a 160, and go back to happy escapism by having Kotori change her mind due to The Power of Friendship (tm) and/or The Power of Love (tm) then this latest shift seems pointless to me.
In fact, it would make it seem to me like Love Live! is half-assing it all-around.
Half-assing the fantasy by denying Muse entrance into Love Live!, but also half-assing the edgier realism shift by not following through on Kotori leaving Muse.
All of that being said, Kotori changing her mind would certainly not ruin this show for me. Love Live! has been an awesome and lovely ride regardless, imo.
