So true.That is one sorry... excuse to NOT heed Lord Jesus' Own Words there in Matthew 24:29-31 and Mark 13:24-27 about the events of His future return and gathering of His Church AFTER the tribulation.
The last phrase of Matt.24:31 is about the gathering of the 'asleep' saints which Paul said Jesus will bring with Him from the heavenly. Paul said they will be RESURRECTED first (1 Thess.4:13-16).
Then the last phrase of Mark 13:27 is about the gathering of the saints that are still alive on earth, the very 1 Thess.4:17 Scripture that Paul taught.
That Jesus mentioned His angels will be involved in that gathering does not change those Scriptures being about His coming after the trib, and gathering of His saints to Himself.
After the 7 yr 70th week ( postrib) Jesus gathers us from heaven as your verse indicates.