I also really don't like this change, but you have to understand why it matters for you. If you just wanted to be able to store different types in an index - y

I also really don't like this change, but you have to understand why it matters for you. If you just wanted to be able to store different types in an index - you still can, just that the type will not be stored in a meta "_type" field but in a document level "type" (or whatever) field. Of course, the API does change since it's not in the URL and if you're creating custom doc ids you'll probably have to include the type in that (comment-123, post-123). So it's annoying, but I think mostly something that can worked around. If you're using multiple types for parent-child, the situation is more bleak. They are still going to have a "join field" but there can only be one type of relation. While often this is ok, there are definitely reasonable use cases where it's not. Currently the traditional parent-child hasn't been removed from the core because they need to support 5.x indices. But it will be phased out unless there is a big uproar.