Greek scribes may well have seen some inter-textual connections between the OT verse and the NT verse in question, after the Apostle John wrote in words the visions given to him from heaven. However, the job of a scribe was to faithfully copy the manuscript before him, not to make (or even offer) a commentary on what it said. Scribal work demanded dedication to accurately making fresh copies of worn-out old copies. As Christianity grew and time passed, the work of scribes came into great demand so they would have a massive amount of writing to do, making new manuscripts.
Those scribes who wrote copies of the LXX had good reason for using the Greek word for 'destroyer' in Exodus 12:23, and the Greek word for 'Death' in Revelation 6:8 but that is not what this question is asking about. Their job was simply to copy what had already been written. Scribes who dealt with both verses may well have had thoughts about inter-texuality. They would have noticed many intriguing details in the course of their work, but we cannot know what they thought unless they wrote that down somewhere; they could not possibly add addendums to the manuscripts - that would have got them fired!
However, a link is given to another question in Stack, with various answers given about what others thought on the matter. Evidence is offered regarding a perceived link between Apollyon and Apollo, for example, and this from various scholars of ancient Greek culture, and from experts in Classical Greek. Yet neither such pagan history, nor language points from a form of Greek not used in the writing of the Bible will help answer this new question. Some who answered that old question pointed out that it was wrong and misleading to try to link Apollyon and Apollo, or even to try to link General Titus into interpreting the Revelation regarding the rider of the pale horse, Death.
If ingredients additional to those used for producing the Bible are looked to, then a new product will emerge. And what will be offered will not be what those directly involved with writing and copying the Bible manuscripts produced. Scribes stuck to the 'ingredients' before them; many later scholars, however, were inclined to scratch around for new, novel elements to add to their mixture. So, my answer to the main question is that the need is to look to later scholars, not biblical scribes, for an answer further to what those verses actually state.
The other part of the question is, "can the preservation of different words here be seen as the later Greek writers, such as the author of Revelation see no common ontological connection between the destroyer angel of LXX and the "death" horseman?" Different words are rightly preserved despite a similar but uncommon subject of an Angel of Death at the Exodus, and the symbolic rider of Revelation's pale horse, named 'Death'. Exodus describes an invisible function of destruction carried out at one particular time upon one particular group of people living in Egypt, with very visible results that have gone down in history. Revelation depicts in symbolic language what God wants all his people to know about world events from the time of Christ's ascension to his return; spiritual events that are unseen to those who take a purely material view of world events. They cannot understand the deadly effects of those symbolic riders over the centuries as being a direct result of God's judgments on much more than the mere nation of Egypt. But insofar as Death destroys, there is an inseparable inter-relatedness between the two texts in question.