Okay, if what people say is correct and there's supposed to be another timeskip, here's what I see going down.
We get to Wano. Whole Cake and Reverie is done and the final fight is about to commence. Luffy and Law vs Kaido. I see Kaido wrecking them in every meaning of the word. Luffy will be tired as hell after the Big Mom problem and Law just can't beat Kaido on his own. So, Luffy is near death and Law has to run away with him. Law does the immortality surgery but (something happens to Law too) Luffy goes into a coma because of it for another 6-10 months until he comes back in full strength and someone has to stay with Luffy and Law in hiding while the crew continue on together. I think Nami or Chopper stays behind along.
During this brief timeskip:
-Coby can get more powerful.
-Shanks is on the verge of losing his Yonko status because of certain events. Maybe Buggy intervenes somehow
-BB gets a WB like fleet with two more commanders. They get to Pirate King level and maybe he gets a new DF. Aokiji has to make big moves in the crew too.
-Jimbei and someone else joins
-Big Mom or the Revelutionnaries move to Elbaf as their new base
-The Whitebeard crew are defeated and executed
-Hancock resigns/revoked as a Warlord
-The Warlord system is kept because the Marines and WG have a new means of controlling them.
Basically, everything has to go to absolute shit and then Luffy wakes up, immortal (maybe with a new scar, feature or ability) and ready to continue. The crew has to become stronger too (all of them at least one form of Haki, Zoro and Sanji learn Conquerer's Haki)
This is how I see another Timeskip going down. I know it's crazy/dumb but whateves, it's my opinion.