Understanding of how thorough the Lord is concerning His word, would it not make sense that He would also have those in mind that will be left behind? I do believe that scripture will be understood well (Matt. 24 etc) for them, by them. We try (you have done an excellent job) to explain scripture that is meant for those who will be left.
Paul said the man without the Holy Spirit can not understand the things that come from the Spirit of God. (1 Cor. 2:14) That’s why so many in our time can’t make any sense of the Bible. The same will be true after the rapture. People who come to a saving faith in those days will have the counsel of the Holy Spirit to guide them in their study of God’s word and give them understanding of it, just like we in the Church have had. They just won’t have His guarantee of salvation. But just as it is now, the unsaved won’t have a clue.