Starting February 17, 2017, the Pokémon TCG: Sun & Moon expansion will be legal for use in Play! Pokémon events. A change to the Special Condition Burned will go into effect the same time. This change was already in effect at Prerelease tournaments for the Pokémon TCG: Sun & Moon expansion.
The Special Condition Burned works a little differently with the release of the Pokémon TCG: Sun & Moon expansion. Between turns, put 2 damage counters on your Burned Pokémon, then flip a coin. If heads, remove the Special Condition Burned from that Pokémon. If tails, the Pokémon is still Burned, and you’ll go through the same process during each between-turns step as long as your Pokémon remains Burned. Note that this rule applies any time a Pokémon is Burned, even if the Special Condition is caused by a card from an earlier expansion.
Source: Official Pokémon site