Now as many of us are hyped about Wano there is yet another arc coming that has a similar mystery and heir. The Reverie arc is going to be massive in setting a precedence and setting for future events, and I see this being set into motion by the biggest mystery organisation The Revolutionary Army.
Dragon, and Sabo a former noble are perfect to cause mayhem and panic at the Reverie, now while this is just a theory I do have some reasons to speculate this
1. We have not seen much of Dragon and his powers, and now would be a great time to see and understand how strong he is in regards to admirals yonkos as such
2. For his organisation The Revolutionary Army the Reverie would be the perfect time for Dragon get a win over the world government along with interrupting their plans and weakening their forces
3. Dragon attacking now would also give us the possibility of a flashback to understand Dragon and the reason he started this organisation, and what better time to show it than the Reverie which is the government that he is fighting against so an understanding can be reached
4. Sabo will be attending along with Dragon for 2 reasons the first Reason is due to him being one of the top in revolutionary along with his past against world nobles being shown his relations and power will be needed to damage the world nobles and forces their
5. The other reason for Sabo is Stelly the brother through adoption that Sabo hated will be there, Stelly who would have thought of him dead till now will be fearful and we will see Sabo's rage along with opening more flashbacks to explain more about Sabo's.
6. The final reason, pretty basic is due to both being family members of Luffy, and knowing very little about Sabo and Dragon. It would be an excellent time to delve into their past and to show their strengths along with what drives their reasons against the world nobles and government, along with the full power and meaning of their cause.
Edit: read it wrong and realise I made a mistake not thinking. You are right about the normal noble I just grouped them together when typing.