So it seems they are finally doing something about the people who like to stall in battles.
PvP Pet Battle Delays
This is actually something we're planning to address in Patch 5.4. Simply put, round timers in PvP Pet Battles will get progressively shorter for a player who takes more than 15 seconds to issue a command during their turn. This change is planned to take effect in a future PTR build, so please be sure to test it out and share your feedback with us!