This term used in 2 Thes 2:1-3 αποστασια
' apostasia '
used only once within the New Testament
however used several times in the Old Testament.
The passage of verse in the the NT are not all the same.
21st century Greek - Rome's manuscripts - Byzantine Text
The argument that the Catholic manuscripts being older
make it more accurate is non sensical, if the text has been altered at outset, is still inaccurate.
But what is clear Tyndale saw the difference and went against the grain of his day 1534 and saw it would be GOD whom would see the EKKLESIA departed from earth
'there be a departing first '
within this passage the 'Ekklesia' simply can not depart by themselves
[ the church simple can not depart of own accord ]