Geneva is a venerable text, but the sense of “departure” in 2 Thess. 2:3 is settled, and it is the sense of departure from a position of orthodoxy, from faith, from a set of beliefs or ideas; falling away from faith; rebellion against tenets of faith; revolt against orthodoxy or tenets of faith — there is no whiff of meaning in all agreed-upon scholarship that admits the sense of departure from a geographic or physical position.
You’ve seriously got to give that up; it’s not what the text is conveying, and it’s hampering you getting clarity on other related texts. 2 Thess. 2:3 does not refer to the rapture, no matter when your eschatology says it’s supposed to happen.
The context is staged as regarding the gathering together unto Him, as amoreperfectunion pointed out eloquently.
The Greek word apostasia can be used both to refer to departing from the Judaic traditions (as is the current pc consensus) and it can also be used to convey a meaning like a ship disappearing over the horizon.
Have you ever considered that Paul would use word that way since his theme in the passage is 'The Departure' as Jesus gathers us to himself?
2 Thess 2:1 Now we beseech you, brethren, by the coming of our Lord Jesus Christ, and by our assembling unto him,
2 That ye be not suddenly moved from your mind, nor troubled neither by spirit, nor by word, nor by letter, as it were from us, as though the day of Christ were at hand. 2 Thessalonians 2 1599 Geneva Bible (GNV)