Google is yet to release Android 5.0 Lollipop for existing Nexus devices. The release might have been held up by a Wi-Fi bug that was draining battery and now the company is expected to push out this update in the coming week. It just so happens that Motorola has started its soak test for Moto X Android 5.0 Lollipop update even before Google has pushed out the OTAs for its own devices.
Ample evidence has surfaced online from folks who have been invited to participate in this soak test. Plus Motorola itself published the release notes for this update online before pulling them, but it did become clear that a soak test for this update is well underway.
A soak test is basically when the update is rolled out to a select group of people, who then test it out and try to find any bugs. If bugs are found the OEM gets the relevant feedback and patches them up. Once it is decided that the software is ready for public consumption, it is then release to anyone and everyone waiting for it to drop.
It can not be said for sure right now when Motorola is planning to release Android 5.0 Lollipop for the Moto X. Though it has been one of those OEMs that releases updates for flagships fairly quickly, hopefully it will stick to that this time around as well.