Hi there. I know that this would probably need lots of coding and all, but here’s my suggestion. You saw the title There could be a sort of waiting room or list. When you send a Pokémon, it goes there and you get another that’s here already. Either you get the oldest one (the one that’s here for the longest time) or a random one. You could choose to get a Pokémon back or not. I remember on another site, when you released a Pokémon it went in a "Shelter" and when you went on the page, you could see Pokémon released by other people and choose some to adopt. As there were many Pokémon in there, every time you refreshed the page it showed other ones. I think there were limitations, like 1 Pokémon per refresh or 5 max per day or something. Also if there aren’t enough Pokémon anymore, there could be randomly generated ones (if this is even possible). (I was writing as I thought so it might be a bit messy. It’s basically a bunch of suggestions for you to pick some)
Hey, not a staff member but oh well. This looks like it would extremely hard to code and I know that they are still struggling with getting normal trading to work. Not to mention that they are working hard on other stuff at the moment, like the new theme. So in the foreseeable future, I don't think this is really viable to do. It does sound like an interesting idea.
I absolutely love the idea and it's one that will definitely be added to a list we have running for future stuff. Hopefully we get the resources to make this a reality! Thanks for the suggestion