Although Android 6.0 Marshmallow has been live for months now and many manufacturers and carriers are working towards pushing that to various devices, there are still phones out there which haven't been upgraded to the most recent version of Android Lollipop. Version 5.1 is what many smartphone owners are currently working with, and now those on Republic Wireless which are using the 1st Gen. Moto X are close to being part of that overall number of Android phone users. According to Republic Wireless, 5,000 1st Gen. Moto X users will be included in a soak test for Android 5.1 Lollipop starting today, although it could still be a few weeks before everyone has been moved over.
With soak tests for newer versions of software which is typical for Motorola devices prior to sending out the update in full force to everyone, the soak will have to result in a desirable outcome. Republic Wireless states that if the soak test goes well, then they expect to begin sending out the Android 5.1 Lollipop software update to users as early as January 20th. They won't be sending out the software all at once, however, and instead will be pushing out to users in 20% increments likely to make sure the software push goes as smoothly as possible.
There's no way of knowing how long the official push will take once Republic Wireless has started it, as it could be anywhere from 5 days to a couple of weeks or more. Why it's taken so much longer to get the software update to Android 5.1 started for Republic Wireless compared to other carriers is unclear. AT&T started and soon after temporarily suspended the update to 5.1 for the 1st Gen Moto X back in the middle of July, while Sprint started the update push to Moto X 1st Gen users on their network back in the middle of November. As for what users on Republic Wireless can expect as part of this update, the release notes state various fixes are included such as a fix for delayed dialing condition, a fix for calls going straight to voicemail, and a fix for the MMS error users have been getting which cause the messaging app to crash, all in addition to the standard changes that Motorola initially mentioned were part of the update to Android 5.1.