Update 4/5/19: Sony put the Android Pie update on hold after it was bricking Xperia XA2 devices in Russia. The update is now rolling out again in the country, according to Xperia Blog. The original story follows.
Android Pie rollouts are in full swing for non-flagship devices of OEMs, and the update love is spreading to more and more devices. Sony is rolling out its Android Pie update to Sony Xperia XA2 and Xperia XA2 Ultra users in the region of Russia, Belarus and Kazakhstan. While the update brings in new features and an Android version bump, it is also packing in a nasty surprise for some users, unfortunately.
Sony Xperia XA2 (and XA2 Ultra) are receiving an Android Pie update with the version 50.2.A.0.342 with an update size of 946.7MB. This update features a few changes like a new notification style, changes to application UI, new volume slider design and a new camera app, along with a few other smaller changes.
While some have been able to successfully install the update through the official OTA mechanism, others have not been so lucky. Some users on 4PDA.ru are reporting that the update is bricking their device. There are display artifacts on boot, and the touch screen is unresponsive. The update breaks TWRP access as well as the TA partition (that is responsible for DRM and warranty). Users have also been unable to recover the device using the Sony Companion software as the software ends up downloading the same firmware. There is no workaround to the situation yet.
Sony Xperia XA2 XDA Forums Sony Xperia XA2 Ultra XDA Forums
At this stage, we would advise Xperia XA2 and Xperia XA2 Ultra users to not install this update. You can try your luck and see if it works for you, but keep in mind that a lot of people have reported bricks, so it isn't a one-off scenario. As there is no clear workaround available yet, or any way to determine if the update will successfully install or not, or a way to resuscitate the device (other than going to the official service center) it is advisable that you do not update to Pie at this stage. Hopefully, Sony will figure out the cause of these bricks and rectify the mistake.