Actualy, i just realized that,
Turalyon A paladin, Kurdran a gryphon rider, danath a mercinary alleria high elf ranger and Khadgar the human mage were not on draenor when it collapsed on itself.
At the end, it says that the surviving humans traveled into the twisting nether to escape. So there is a good chance. although Ner'Zul got caught by the legion in the twisting nether.