When it comes to update roadmaps, manufacturers seem to miss their target rollout dates more often than not, so it's always a nice surprise when an update shows up early. Sony is now sending out the Android 11 update for the Xperia 1 and Xperia 5 in some markets, earlier than the February date originally given (and even ahead of the newer Xperia 5 II).
The update comes about a month after the Xperia 1 II's. It carries build number 55.2.A.0.630 for both the Xperia 1 and Xperia 5, and comes with the December 2020 security patch. XperiaBlog notes that Sony has not included the fancier Photography Pro app from the newer Xperia flagships, and that there's no change to the camera interface. That's unfortunate, but at least you still have the new stuff that Android 11 brings to play around with.
As of right now, the update only seems to be available in the Russia and Southeast Asia regions, but it's sure to spread soon enough.