>>542268016
I feel like if they add a Yordle, they have to bring energy that contrasts with Teemo. Teemo is pretty bright and weird and cute and Heimerdinger is more of that, but older.
Out of the remaining Yordles, I see Vex, Poppy and Kled and even Rumble having the greatest chance of getting in.

>>542085934
It'll probably be a female yordle and either the opposite of Teemo or someone serious. I see either Vex or Poppy. If they go male, it'll be Kled.

Gotta think in terms of game mechanics, too. Like which of these champions would provide the most unique or interesting playstyle?
>Vex has a potential Zato function
>Poppy has a lot of CC
>Kled is a mobile chaotic fuck and possibly a Sin function