you still haven't let go of what kishi did have you? its understandable the bastard deserves all the criticism he gets especially from females anyway regarding seren she's actually the most developed female companion we've seen so far and i could see ash with her the xy writers have taken the anime in a new and better direction after the kitten that was best wishes so much so that they created a character that has a past with ash you could sy they did a retcon like how the last as but unlike hinata while serena admires ash she found a passion to and worked hard what is hinata's passion nothing at all lol
I got to agree with you man, to me Kishi is just an after thought at this point. Good points regarding Serena, She's gone through alot within the course of the series. I mean I love Dawn and Misty, but their characters in some way have remained the same from the beginning. It took a while to get Serena's goal, and that's something I really liked about her. It wasn't set in stone it took time before she decided, and I think that's very realistic.
In terms of the anime, not movies like 2000 or Pokemon Heroes, Serena is one person who genuinely has a connection Ash before he became a trainer which really sticks out about her. Argubally she is the first pokegirl that came into his life. Also keep in mind that Serena helped Ash perfect Ash-Greninja and Ash in a way inspired her to do her very best in never giving up. Let's not forget how many characters have noted and teased Serena about her feelings towards Ash. Not to say, I'm pretty confident, but on a scale I will say 75% of me believes Serena will travel with Ash to Alola.
Also keep in mind it has been stated in the XY series that you'll grow closer to someone if you give them a gift under the tree, and What exactly happened lol.

Not say that everyone else is wrong, cause it's your opinion. I'm just bringing up points, if that makes any sense.