It appears that HTC is actively releasing an Eye Experience software to its flagship phone via OTA update, almost all of HTC’s flagship phone in the US could possibly get this selfie-friendly software updates, including the T-Mobile HTC One M8. Previously, the updates have also been rolled out to the two major US carriers, like Verizon and Sprint, while the AT&T model still in the certification stage. The great thing is, since this device has been supported by HTCDev to unlock the bootloader, root is not a hard to get.
Just like software updates that already released by others, the software version 3.32.531.2 for T-Mobile HTC One M8 brings the Eye Experience software and also the updated KitKat release (Android 4.4.4), which most likely just a Google security patch related to OpenSSL vulnerability. So the HTC Eye feature could be the most noticeable changes in this software release. Although it is not a major update, the update file size is quite large, greater than 250MB.
There is an absolute requirement if you are planning to update the T-Mobile HTC One M8 with Android 4.4.4 via OTA, you should run the stock HTC Sense firmware and also have a stock recovery that’s built specifically for your current software version, otherwise, the OTA installation will be failed. The custom recovery like CWM or TWRP Touch Philz won’t be able to process the official OTA update.
As we said earlier, root can still be obtained when the phone’s bootloader already unlocked. There is no need to re-lock the bootloader to update the software, so you can simply push the TWRP via fastboot command right after updating the phone.
Once the TWRP installed, then boot into recovery, it will say that there’s no root on your phone, and then ask you to set it up, however, you can also manually flash the SuperSU zip.