Now that Android 6.0 Marshmallow is rolling out to Google's first-in-line Nexus line of devices, and HTC is soon to release the One A9, the first non-Nexus smartphone running Android M right out of the box, Android update season is upon us. And it's looking like the third generation Moto X Pure Edition (or Style) is poised to be one of the first to upgrade.

The Moto X Pure Edition is Motorola's 2015 flagship smartphone, which was released about a month ago. Now it looks like Motorola is hard at work preparing the Android M update to run on its top device.

According to GottaBeMobile, Motorola insider David Schuster has posted a Google+ update meant to quash rumors that the company was already running so-called "soak tests," or small-batch test updates, on the 2015 Moto X. However, his post only helped confirm the progress the company is making preparing the Marshmallow update for the handset.

"There have been a couple reports of a Marshmallow 'soak test' that has started for Moto X 2015 Pure Edition," Schuster said in the post. "Just want to make it clear that we have NOT started a formal 'soak test.' We have started a small TestDrive for the Marshmallow upgrade on Moto X 2015 Pure Edition."

So while the Moto X is not undergoing a full soak test, Schuster nevertheless confirmed that the first stages of the upgrade are indeed underway. Schuster said, "We will be conducting these tests for the next couple of weeks. Pending the feedback during this test cycle will determine the timing of a full soak test."

This likely points to an early November final testing phase and a final feedback cycle, followed soon after by an OTA rollout of Android 6.0 Marshmallow to all Moto X Pure Edition handsets.

Even without Schuster's inside information, there are several basic reasons to believe the 2015 Moto X will be one of the first non-Nexus smartphones released running Android Lollipop to get the upgrade.

First of all, the 2014 Moto X was the first non-Nexus handset to get the Android 5.0 Lollipop update in late November, just a couple of weeks after its release.

Secondly, the Moto X 2015 was sold completely unlocked and carrier-free, meaning the smartphone is uniquely able to avoid the extra weeks of waiting for carrier testing before rolling it out.

Finally, Motorola preloads some apps onto the Moto X Pure Edition, but the operating system largely remains pure Android (hence the name), obviating the need to spend more time readjusting the UI for each Android update.

It all points to a similar timetable for the Android 6.0 Marshmallow update on the 2015 Moto X as last year's Lollipop update on the 2014 Moto X. And possibly sooner.