An Apex Legends leak from data miner That1MiningGuy suggests King's Canyon could become available to squads when Season 4 ranked play starts the second split.
Respawn Entertainment made the announcement of the two-split season before it started, but only made it known King's Canyon would be the map for the second split. It was never specified on whether normal squads would be able to play on King's Canyon as well.
Apex Legends Leaker Believes King's Canyon Will be Available to Squads
King's Canyon will return to ranked mode on March 24, the start of the second split. And based off of That1MiningGuy's tweet, everyone could have a chance at playing King's Canyon again. His information is based on datamined code and has largely been correct over time.
As usual with leaks, the information has not been confirmed by Respawn Entertainment. The company is probably too busy dealing with bugs like hitbox problems to deal with leaks or information about Apex Legends Season 4. The hitboxes are being distorted by Revenant's ultimate Death Totem, as the totem itself blocks bullets that appear far outside its in-game model. If you're having similar problems, you can report them on Respawn's forums.