9:127 Foreshadowing
If individuals conspired to add something to the Quran and God informed us that He would preserve it, then He would already have known of their scheme and planned accordingly.
15:9 Absolutely, we have revealed the reminder, and, absolutely, we will preserve it. إِنَّا نَحْنُ نَزَّلْنَا الذِّكْرَ وَإِنَّا لَهُ لَحَافِظُونَ
13:42 Others before them have schemed, but to GOD belongs the ultimate scheming. He knows what everyone is doing. The disbelievers will find out who the ultimate winners are. وَقَدْ مَكَرَ الَّذِينَ مِنْ قَبْلِهِمْ فَلِلَّهِ الْمَكْرُ جَمِيعًا يَعْلَمُ مَا تَكْسِبُ كُلُّ نَفْسٍ وَسَيَعْلَمُ الْكُفَّارُ لِمَنْ عُقْبَى الدَّارِ
We see from examples in the Quran that God already plans for these things in advance in ways that we can’t even imagine. For instance, God informs us of the following:
8:42 Recall that you were on this side of the valley, while they were on the other side. Then their caravan had to move to lower ground. Had you planned it this way, you could not have done it. But GOD was to carry out a predetermined matter, whereby those destined to be annihilated were annihilated for an obvious reason, and those destined to be saved were saved for an obvious reason. GOD is Hearer, Omniscient. إِذْ أَنْتُمْ بِالْعُدْوَةِ الدُّنْيَا وَهُمْ بِالْعُدْوَةِ الْقُصْوَىٰ وَالرَّكْبُ أَسْفَلَ مِنْكُمْ وَلَوْ تَوَاعَدْتُمْ لَاخْتَلَفْتُمْ فِي الْمِيعَادِ وَلَٰكِنْ لِيَقْضِيَ اللَّهُ أَمْرًا كَانَ مَفْعُولًا لِيَهْلِكَ مَنْ هَلَكَ عَنْ بَيِّنَةٍ وَيَحْيَىٰ مَنْ حَيَّ عَنْ بَيِّنَةٍ وَإِنَّ اللَّهَ لَسَمِيعٌ عَلِيمٌ