II mean Ash isn't the only person in Kalos who owns a member of the Fletchling line so imo, it seems silly to assume that the Fletchinder has to belong to him and nobody else.
To what end?
I mean sure if this a straight up Fletchinder, and not any kind of evolution episode, then sure, fine.
But if this is an evolution episode, to what end does it serve to watch someone else's Fletchling evolve, when Ash has a Fletchling?
Furthermore, even if this wasn't an evolution episode, what purpose would it serve to show that other people besides Ash has something of that particular evolutionary line? Why is it so necessary, to show that other trainers share Pokemon in common with our protagonists.
Doesn't that defeat the purpose of giving the main characters certain Pokemon, they're going to be shoved down our throats either by being wild or belonging to someone else?
I mean it's one thing if said character isn't going to have the evolved form, and they are showcasing the evolved form, but do you really think Ash's Fletchling is going to remain unevolved? Is it going to die, or something?