It’s still clearly something that you would have to be born with. Otherwise, why wouldn’t the brotherly bond between Anakin and Obi-Wan be considered a dyad? Or between any Jedi/Sith pairing in general?
EDIT: Already know what your response is. Yes, Snoke bridging minds might cause the dyad to form, but then why hasn’t that been done before? It’s just a massive plot hole across the saga. Furthermore, Kylo says that the effort to project like that would kill. If it kills Luke, then why doesn’t it kill Snoke? This suggests that he is utilizing something that has always been present.
It can just be explained away as the ‘dyad’ being a rare occurrence in the Force, “unseen for generations”. Doesn’t mean other people’s bonds aren’t as strong, just that something about Kylo and Rey and their relationship ‘triggers’ a dyad to form between them. It’s not necessarily just Snoke’s meddling that forms the dyad, though it unmistakingly makes their relationship grow. In that way you could say the ‘dyad’ begins to form from the moment they meet. I don’t think it’s a plot hole to introduce new Force concepts, the Force shouldn’t be limited to what we’ve seen before. Snoke’s mind bridge and Luke’s Force projection were two different things, and in that sense the dyad is it’s own new concept aswell.
Snoke sure seemed to be a mere meat puppet in a cursory reading of TROS, IMHO. He’s every voice in Kylo’s head and essentially just Palpatine with a paper mask. And if that’s so, it makes little sense that Snoke seemed acutely aware of Rey and Kylo’s connection and Palpatine seems surprised by their dyad-ness. Unless the dyad thing was just like, “Oh, well I didn’t know it was THAT far.”
That’s why I feel it’d be better to avoid such confusions and let them be two distinct characters.