So we've done a couple of these in the past. Basically post any fantasies you can think of that apply some sort of ABDL scenario to a large population, whether that means you have a secluded hippy commune of sissy diaper slaves or you have an elaborate fantasy world with extensive worldbuilding surrounding how there's a master race of diapered elves.
If you don't already have a globalization scenario in mind, I thought I might make it a game by throwing some conditions at you guys to generate ideas.
1. You can make a magical wish that must apply to yourself as well as part of the human population. Can only be up to 80% of the human population, or you can choose to only have it affect a certain subset, such as men, women, blue eyed people, etc. Wish can only affect people's minds and bodies, not the planet itself or any objects. How does it play out, and how do you accomodate for the unaffected people with your wish.
2. You are allowed to establish your own country, where once people become citizens, you can legally inflict whatever diapered fuckery you want on them. However, people must immigrate to your country willingly and you must be upfront with what sort of ABDL stuff you will do to them there. How do you convince them and what will you do?
3. You can create a personal fantasy world, but your building blocks are the tropes and cliches from the worst ABDL stories you've ever read. Would you still do it, and what would that world look like?