Having a reason listed would be nice. I picked one off the list that I couldn't figure out from the name alone why it would be banned and decided to take a look and see why. I was apprehensive. What horrors was I about to see?

Couldn't figure out why it was banned from the content alone. I looked it up and found a website that has their defederated instances list and the reasons. I didn't see anything that matched the reason given, but I didn't care enough to keep digging further.

I think the list is shared among a few instances.

Is there any chance instances will start (or already are) blocking other instances based on instances they're linked to? Similar to the way some subreddits would automatically ban users for participation in other subs, it could further enforce echo chambers. If Lemmy.world is a little more open, I'd hate for it to get blocked by somewhere like Beehaw just for that.