After the destruction of the earth during the Xianjie, what will happen to those who have not reached the Guangyin Heaven?

It will not disappear forever. People who have not emerged from the six realms of reincarnation will only continue to reincarnate. In addition, the concept of time is not equal for different sentient beings. As for where sentient beings will go, leave it to those who are experts in telling lies. For example, if the earth is burned down, you can still immigrate to distant outer space. At that time, people are no longer human and have transformed into other existences due to karma (such as the difference between sentient beings in the six realms).