Sorry, should have been more clear. You said:
whereas in the actual films the dyad was formed because Rey and Kylo Ren were the respective grandchildren of two separate Force-sensitives.
which is not the canon answer anywhere, mostly because it makes no sense whatsoever. Sure, maybe you can interpret that from the movie, but it isn’t suggested at all.
Why else would Kylo point that out, more specifically right before he reveals he and Rey are part of a dyad?