The remaining Whitebeard Pirates, Kuja Tribe (due to the island no longer being protected), Perona, Bon Clay with the Newkama (They will find their way out somehow), and Sky Folk (The Shandarians and Skypeians would be interested in checking the Blue Sea one day. Gan Fall will probably remain as God and not leave the island) join the Strawhat fleet. I would also say the Galley La Company and Franky Family if not for the fact that they are a business first and explorers last.
Vivi rejoins the Strawhats with nowhere else to go (due to Imu being on her tail)
Someone else inherits the Snow Snow Fruit, Calm Calm Fruit, and Sala-Sala Fruit, Model: Axolotl (if the anime filler of the fruit being killed by the poison isn't canon).
The Strawhats will gain more territories to protect (Dressrosa, Alabasta, Shandaria, Drum Kingdom, Wano, etc)
The Sunny will get a final upgrade that will be stronger than it was since Water 7. Now is the time for Franky to really improve the ship for the final war.
The Strawhats will get a final 3 crew members after Jimbe. Then that should put them on the same level as the Whitebeard Pirates. At the same time, I see Blackbeard recruiting more members in addition to their newest member Kuzan.
The Strawhats will upgrade their weaponry (Usopp upgrades his Kabuto, Brook gets a new cane sword with greater soul control, Chopper will make a Rumble Ball that gives him a new form to replace the lost Jump Point as we know it and Arm Point were combined to make Kung Fu Point, Robin will become comfortable using more weapons like knives like her older days, Franky will upgrade the Franky Shogun to have flight and other addition weapons, and Sanji will master his Raid Suit while asking for upgrades from Germa). I know the last one is controversial due to Sanji hating his family, but it is clear he will need to have better control of the suit for it to be a great asset.
All Yonkou will die in the end. Sorry, but even I get the feeling Shanks will be the next Ace and somehow lose his life to Blackbeard or another strong force.