I 100% agree that it's the owners choice if he decides to block content. But as far as I know if a instance is defederated and the instance owner doesn't publish a block list, users on the server would have no idea it existed in the first place.

There are already a couple of search engines that show instances. Maybe if some of the developers could add categories so people could find things they are interested in. This could be a useful tool for building communities. As long as it's an uncensored database of indexes I think this would be great. If you know one that is indexing instances by category please post it.

I'm sure instances will post guidelines and rules once they get everything straightened out. I'm just a strong advocate for personal choice. Once again I understand why some people want moderation and I understand eventually it may well be needed for some communities. As long as the owners are open about this that's fine, but not all operators are going to be transparent with these policies.