Verb
rapiō (present infinitive rapere, perfect active rapuī, supine raptum); third conjugation iō-variant
1.I snatch, grab, carry off, abduct
Perhaps Jerome's use of 'carry off' or 'I snatch' (in the twinkling of an eye is quick!) is why the first several Bible translations translated 'apostasia' as departure, and departing, as seen in 2 Thess 2.
My ear brother, I have checked this out, and nowhere in Strong's concordance, or Thayer's Lexicon, or Roget's Thesaurus, or in Sisson's Synonyms do I find anything that equates the Greek apostasia, our term "apostasy," with anything about the kind of "departure" your interpretation demands. Apostasy/aposrasia is always translated as having the sense of turning from that which is good and right towards that which is wrong and unmoral: deviation from rectitude, perfidy, heterodoxy, seceding from the true religion, divorcement. Its converse is repentance, of turning to God from idols, so to speak. The definition of apostasy carries with it moral terpitude.
It is not just a movement of a person from here to there, for which the process of leaving would be interpreted as departure. So It is not very likely at all that the "falling away" of 2 Thess 2:3 would be interpreted in any sense as being anything but firm and permanent disloyalty and departure from God's ways. And it is always at the instigation of the apostate himself actively.
It can have nothing to do with the passive yielding to the summons of Christ to pluck us up to meet Him in the air.
So I think you'd better give up that line of reasoning as to the use of that verse to support the harpadzo. In any case, it is not needed for the spiritually mature discerning believer anyway, and arguing further about it is simply not profitable.
In the end, it is always going to boil down to salvation by faith or salvation by works. So when we see the drift of someone being other than simple inquisitiveness and desire to learn, it is economical to just decline to bandy words about it, and get on to someone else who wishes to know more about Jesus. Eh?