Kylo appeared in front of Luke because the dyad includes the ability of material exchange also demonstrated in TROS. If anything, that should be enough to prove that whatever “Snoke did” included material exchange, which is quite frankly just ridiculous. So obviously there is more to the story.

Also, you seem to be ignoring my point that there is still a twist revealed by Snoke: he orchestrated Kylo appearing vulnerable in order to lure Rey in. The mind link is not necessary for that twist to work. Nothing is being undermined.