With release 188.8.131.525 to the official league plugin, there a few updates that will be available to league servers.
Spawning on late entry
Since the days of Duc and GU, there has been the accepted practice of players killing themselves on their first spawn when they sub or join a match late in order to spawn randomly and not have a particular advantage. Not all new players knew about this practice, so an update has been pushed to match servers where players will no longer spawn at their base if they join 30 seconds after a match has started.
Players aren't reported correctly in matches
If a player would rejoin late in a match, they would not be reported as participating in the match. Sorry about that! Your dedication to playing in a match will now be reported correctly.
Getting kicked on join
With the introduction of maps with different colors, if a player would join a non-existent team (e.g. joining Purple on a Duc map) they'd be kicked. Players will now be forwarded to an existing team.
Self-capping during matches
Well, it doesn't happen often... But it may. Self-caps are now reported against the team who self-capped.