When does the server send down new documents?

Just wondering what would happen in this situation:

Client uses this method

Meteor.methods({
  insert() {
    Coll_A.insert({field1: 'hello'});
    Coll_B.insert({field2: 'world'});
  }
});

The client is subscribed to both Coll_A and Coll_B in a single subscription that returns an array of cursors. Does sub.ready() wait until both new docs are in the client’s Minimongo? Or does sub.ready() happen twice (i.e. once for the new doc from Coll_A and once for B)?

I believe I’m right in saying all this:

sub.ready() is true when the initial set of documents have been sent to the client. If you are inserting in a method, then sub.ready() will have probably been true before this call. After which the docs are sent as-and-when they are detected as having been added to the collection by Oplog-tailing or long-polling.

Conversely, if you subscribe after this method is called, it would wait until all docs in Coll_A and all docs in Coll_B are sent to the client.