When I was a freshmen in college, In my first week, I joined one of the abdl networks, I dont remember which one it was, this was back in 2006. It turned out that an upper classmen was also going to the same college as I was, and wanted to meet up.
I had never met someone else who was an abdl before, he was friendly enough, although he was a bit more enthusiastic about certain things that I was hoping to avoid or just discuss? we ended up going to a walmart and purchasing nappies, and then went to a mall and put them on in the changing stalls, Unfortunately, to me it felt awkward, and I dont think we had anything remotely in common aside from an interest in nappies. He wanted to get together a few times after that but I politely declined.
so..essentially, if they are a person you would enjoy spending time with in a non abdl scenario I think that it would not be a breach of privacy to spend time in a abdl mind state.