Motorola already announced a list of devices that will get Android 6.0 Marshmallow a couple of days ago, it wasn't very shocking but it left some handsets stuck with the current hardware. One of the devices that is confirmed to get the update is the recently announced Moto X Pure Edition, Motorola's recently announced flagship device which was unveiled during IFA 2015 in Berlin at the beginning of September, which they plan to sell through the Moto Maker website as well as other retailers online and in stores. The company has been known for using a very light skin on their recent hardware and is an almost unmodified version of stock Android like what's found on Nexus devices, enhanced only with some features like additional voice interactions and some functions that use some of the integrated sensors.
Some members that are part of the Motorola Feedback Network are getting invitations by email to preview new software on their Moto X Pure Edition. It mentions that only a limited quantity of devices will participate in the program that's all about getting feedback from their devices, so those interested should check their email and act fast enough to answer a survey that could end up landing them a spot in the program. It's not uncommon for Motorola to provide these kinds of soak tests, but the email doesn't contain any information towards what to expect from the software.
It might be too soon to think that this could potentially be the soak test for the Marshmallow update as it was only released last week to Nexus devices, but since there have not been many reports about bugs or malfunctions on the existing software, it is a possibility. Since they don't make many changes to the operating system, this could be an early build to detect bugs so they can then release it to a wider audience in the near future. Some of the changes that will be included in the update are the new Doze Mode, Google Now On Tap, Android Pay, Direct Share and simplified Volume Controls. Moto Assist and Motorola Migrate will be removed from the included apps, as they are considered redundant with some of the new features.