This is done when requesting `getThreads`... What does happen when receiving a new MMS of 'n' contacts who are not in your Agenda? We are going to use `createThreadMockup`, and there we are not requesting `findByPhoneNumber`, so when tapping on this thread, the info will be ready? Are we going to render the `headers` properly? Furthermore, if the request to Gecko (due to is async.) takes 10 seconds (it's only a exaggeration, but it's for trying to explain my doubt here) and meanwhile you have entered into the thread, When are we going to update the headers? Because https://github.com/mozilla-b2g/gaia/pull/10254/files#L6R992 seems not to be ready for this type of things.