Hi @Ariel_B,
This is effectively what delete (including delete-by-query) does. Deleted documents aren't really deleted until merging. However, updating a document (e.g. to mark it as unsearchable via some other mechanism) involves deleting the old copy of the document and then indexing the new copy of the document, which is more work than just deleting the document.
Yes, this would also involve deleting the documents and then doing some extra work.