I don't think we are on the same page, it might help for you to explain some background?

Deletes don't involve a Document, but a type and optionally a pair of Ids.

But the user might need to read other fields from the object to make a decision.

The deprecated IndexShardingStrategy has a separate method for deletions

That's one of the reasons for it to be deprecated It was very tricky for people to figure how to do that correctly: realize that we don't provide the previous snapshot, so even for an update we might fail to know were to remove the previous copy from. That's why the new implementation is attempting to not expose the option to have add/remove resolve on two different places.

May I guess you're looking at it with eyes of performance optimisation, as the current implementation sends delete operations to all shards?