I keep getting frequent questions in game now because of the recent changes to the channels. The question is typically will the bosses only spawn on one channel or both? My answer will always be the same, and I don't feel like repeating myself.
Bosses will spawn on either channels with double the random chances. The spawn time will still be the same for all bosses. It just has chances of spawning in other places. They do not spawn in only one channel or spawn more than once. It is only one boss to the whole two channels.
For example, if you are looking for Tundro, it spawns in 3 places in spirit shelter before on channel 1 every 5-7 hours. 1/3 chance of spawning in each spot. Now with 2 channels, Tundro has 6 places to spawn total on Channel 1 and Channel 2, so it has 1/6 chance of spawning in any spot. It will still spawn every 5-7 hours. It will only spawn once in either channel.