I can’t take credit for the Idea as it was brought up by someone in another thread, as for the dialogue I think it would be more affective if Snoke alluded to Palpatine as the “Dark Lord”, “Phantom Menace” or “Master of the Sith” soon to reveal himself in the unknown or something to that affect, keeping the surprise for TROS.
Another way to emphasise Snoke’s allegiance to the Sith would be through music and sound, adding the “Sith whispers” from TPM to the opera scene music would give a very Sithy vibe, also incorpirating some sith chants from the acolytes on Exogol would be a pretty good indicator 😉