[jjotto]

It’s also possible that such identification will only be made at the resurrection.

Another teaching is that a prophet, or Elijah himself, will identify Jews and tribes. No reason tech couldn’t help.

[amorphous]

How it all unfolds is a great mystery. A mystery I admittedly don't even begin to comprehend, except for small parts and pieces which seem to make sense. In this case, I envision DNA markers might play a role in identifying those who came out of the original lost tribes of Israel.

I don't rule out supernatural means, it's just beyond my limited understanding and research of this prophesy.

Isaiah 27:12–13 In that day the Lord will thresh from the flowing Euphrates to the Wadi of Egypt, and you, Israel, will be gathered up one by one. And in that day a great trumpet will sound. Those who were perishing in Assyria and those who were exiled in Egypt will come and worship the Lord on the holy mountain in Jerusalem.

Matt. 24:31 And He will send His angels with a great sound of a trumpet, and they will gather together His elect from the four winds, from one end of heaven to the other.