It probably won't since apparently no mechanics where implemented from The Forge, but since Mumsy says she'll follow right after with Billy, we can expect something.
Coins:
Would be given by the Pig King along with the usual Gold Nuggets.
Mumsy and Billy
Would live somewhere in the map. Maybe by the Florid Postern? Who knows. Billy and Her would keep on selling their stuff.
That pink biome
You know how there are 2 Decidious Forest biomes? Take one off and add Candy Land!
Elder Pig, Salt Ponds and the seed-selling-Merms
All of those would now live in the Marsh and keep up with their respective roles
Dishes
Except for the Meatballs, I think all dishes should be added and given hunger/health/sanity values. Those values would get a small boost when plated.
It's not very convenient, since most content would be fairly distant from one another, but then again this is a survival game and shouldn't be convenient; even so, hear me out:
New content: players have been craving for new content. A New Reign feels like a long time ago and this seems like a good opportunity to keep the game fresh.
Don't Stave: The Gorge's content gives further depth to the basic need that the game's named after. Making food becomes more complex and fun!
Farms: Everybody knows farms are very expensive to produce and you can obtain similar and better results with cheaper alternatives (bird cage, monster meat, berry bushes and ice). Having new seeds, cooking stations and dishes that depend on certain farm vegetables (and Gorge's cooking stations) would give farms new purpose.