The new firmware is currently being pushed over-the-air with a version number of ‘01078.00042.16352.500xx’. It isn’t clear yet what the update adds; Microsoft still hasn’t updated its firmware history page, which is strange.
Lumia 650 is definitely getting double-tap to wake with the update – as this is something that can be tested. However, Lumia 550 users do not have the feature despite having the same firmware version.
This same updated was released via the Windows Device Recovery Tool last week, as reported by Neowin. However, updating your firmware with the tool would also reset your device to factory defaults. With the over-the-air update today, that is not the case.
Features such as double-tap to wake are hardware dependent, so it makes sense if not every phone gets the feature in the update – but that raises the question, what else was in the update? That is not clear yet. However, Microsoft will release the changelog at some point; all we can do is wait.
It is great to watch Microsoft support its Lumia devices despite having given up on the brand and (possibly) discontinuing it in the near future. These devices already run the latest Windows 10 Mobile; hopefully, they will keep receiving updates to the newest versions of Windows as well.