Guys, I just had a sudden epiphany and absolutely had to share. If this idea has been brought up previously, I humbly apologize.
So when our original trio parted ways in "Gotta Catch Ya Later!," I'm sure most of us can recall how Brock gifted Ash a boxed lunch, while Misty gifted him a handkerchief to help him carry it.
In East Asian culture, the giving of a handkerchief is meant to symbolize wiping away tears after the departure of a loved one in any form. A few episodes later in "You Never Can Taillow," we actually see Ash using this very handkerchief to clean off his Taillow's beak.
Now we haven't seen the handkerchief since as far as I can Taillow (sorry, couldn't resist), but it would be safe to assume that if he took the gift with him to Hoenn, then he has still been traveling with it all this time later.
To move on to my main point, this is important because, as some of you might know, there is another famous trope involving handkerchiefs in Eastern media, especially in anime and manga. When hinting at a potential romance between two characters, creators will utilize the "returning of the handkerchief". This is when character A will gift character B their handkerchief as a kind gesture when character B is in need of it. Some time later, character B meets back up with character A to return said handkerchief. In some cases, it can be implied that character B returns the handkerchief is romantically interested in character A, and might even understand the implications of the gesture. Since it can't go without being said, this trope was notably used with Serena at the start of X&Y.
So with all of this in mind, it might be a long shot if the writers are even thinking about this small detail at this point, and I don't want to get everyone's hopes up, but if Ash returns that handkerchief to Misty before the end of the series, it is going to rock the Poke Shipping world and possibly serve to solidify them as a future couple.
Hope I explained that well enough. For more details on this trope, here is the TV Tropes entry for further research:
https://tvtropes.org/pmwiki/pmwiki.php/Main/ReturningTheHandkerchief