Basiclly, adding a sort of reward to the people placed in top 100 ahead, apart of the top 3 crowns. Also, this may be according to how played is that tier (Ex: in matchmaking, OU is largely more played than UU/NU/DB) so rewards (could be cash, any common vanity or even any pokemon) are adapted to each tier and its popularity among Matchmaking players. This may lightly increase the competitivity and a sort of value for reaching top 100 in the leaderboards, as well as the number of matches/players