What do YOU want the GMS exclusive content to be/think it is?

Because then they'd have to explain where the fifth main group in the Keep suddenly materialized from. The four imposter monsters we have now are based on the four original guilds. "OH HI YEAH THERE WAS A SECRET COMPARTMENT IN THE KEEP WHERE THESE GUYS USED TO HIDE YEAH SORRY ABOUT THAT"

???

Still not seeing these ''massive ramifications''.

Not like the story of the place currently adds up anyway, they could do anything with it. pineapple it, they could say the Masters created the Pirate themselves or whatever, you get the idea.