Idk man Bliz it's not too difficult to put some incentive in every ladder reset. Top 1-3 gets a glow in the character's signature ability e.g. Holy shield lightblue aura.
Top 1-3 Paladin (lightblue holy shield effect)
https://i.imgur.com/Flithplm.jpegThis is
minimal effort but will give a lot of people incentive (and more drama) to grind for top 1-3 class on every ladder reset. This will satisfy players who want to look unique since most builds kinda look similar endgame.