Yeah at this point I’m fairly certain the dyad budded during the interrogation scene of TFA. I seem to recall people freaking out because Rey “downloaded” Kylo’s training in the novelization of that scene. From that point, it’s up to debate whether Snoke should be the one to enhance it further, or if it should evolve on its own naturally (which is what I prefer).
The whole Dyad thing was JJ’s way to kinda fix that whole “download thing” as well as "light and dark meets up (power wise) from TLJ (just my opinion since that’s just an added bonus to me).
So I don’t disagree with you the whole Dyad thing is meant to be “there the whole time” but it gets confusing with Snoke’s “Mind Bridge” since we the audience see the “Dyadness antics” are shown after what Snoke “apparently does.” (Able to communicate visually, water droplets, etc."
I try to put myself in the seat of your “average” person watching the movie. Regardless of rationale or using “outside sources” (AKA books, etc.) to explain things isn’t really fair for the majority of the viewers. There is rationale that can be implied, IE Snoke didn’t know the full extent of the “dyad” stuff, even if he was an IMPLIED meat puppet / Palps then wouldn’t know … but it is still confusing and gives off the Plot Hole Vibe.
So TL:DR, taking out the every voice line removes any doubt of conflict on what has happened before. Still can keep the “I made Snoke” since it is still fairly ambiguous, especially with the Snoke Vats being turned into Palpy Vats.