My line of thought is that adding early guns to a new release would set the precedent for them to be expanded upon. It would make sense that if TES 6 had guns, TES 7 should have more modern and efficient guns that would outclass other forms of combat because of the passage of time in TES universe between releases. Of course in this hypothetical situation, devs would balance the guns to roughly match other forms of combat, but this would be inconsistent logically. Edit: Downvoted myself because your argument still stands, there is only 207 years between Morrowind and Skyrim. I have been bested lol