You asserted, “No commentary on this verse by anybody in church history, prior to the Rheims, understood “apostasia” to mean anything else.” But the previous Bibles ALL translated apostasia as THE Departure. IF you read the passages prior to and the passages following verse 3, you will see the meaning of the apostasia Paul wrote of. Do I really need to post those following passages to align your vision?
But to insert a pretrib rapture in 2 Thess. 2, is to read into scripture something that isn't there. Jesus set the bar back in Matt. 24, no pretrib rapture there, Paul is merely following Jesus in 2 Thess. 2.
I quote here one of the foremost scholars of ancient times was Irenaeus, I am convinced he knew Greek at least as well as MHGinTN... and the pretrib preachers he follows! He said:
"The apostle thus speaks in the second Epistle to the Thessalonians: 'Unless there shall come [apostasia] first, and the man of sin shall be revealed, the son of perdition, who opposeth and exalteth himself above all that is called God, or that is worshipped; so that he sitteth in the temple of God, showing himself as if he were God. The apostle therefore clearly points out his apostasy, and that he is lifted up above all that is called God, or that is worshipped... he will endeavor in a tyrannical manner to set himself forth as God."