[...] I'm one of the guys who didn't get his blackbytes.
[...] The only thing I changed compared to the previous distributions is the hub.
You have to talk again with transition bot when you change hub.
Are you sure about that? I changed hubs lots of times and didn't have to talk to the transition bot more than once.
Yes. Unless if, by chance, you are back to the same hub when distribution starts again. The distribution bot needs to know "where" to sent you the BlackBytes.
I changed the hub to yours

before the last distribution (pretty sure about that) and got my blackbytes. The only talking I might have done with the bot is saying
hi so that it displays info about the linked addresses, is this what you mean?
Yes. You don't need to register again your address, a simple "hi" to the bot is enough so that the bot knows what is your current hub (and welcome to our hub