When it comes to the release of the newest version of Android, version 5.1, there are some Motorola phones that have been slow to get it. In fact, some versions of these phones are still running version 4.4. The good news is that the Android 5.1 Lollipop Update is on the way for the Moto G (1st and 2nd Generation), the Moto X (also 1st and 2nd Generation), not to mention the Moto E from such carriers as US Cellular, AT&T, Verizon, Sprint, and T-Mobile.
A recent report that appeared on Android Central has given a report from Motorola's own David Schuster, who announced a lot of information about the availability of Android 5.1 Lollipop on various Motorola Moto devices.
For the Motorola G, 1st Generation with 4G LTE, the company is doing a full soak in Brazil Retail today (this source was reported on June 30th). It is possible to go to the Motorola website and read that they are "excited to announce a new software update for the Moto G with 4G LTE by Motorola" and "this update brings Android 5.1 Lollipop to your phone along with other improvements". You should probably check your Settings right now if you are a user of this device.
As for the Moto E, second generation, with 4G LTE, there is a "full deployment for Cricket in the United States today". If you have this phone with this carrier, check out your Settings and see if you can get it.
As for the Moto X, second generation, Schuster reports that there is a full deployment for US Cellular in the United States. There is also a full soak test for AT&T in the United States today, and a recent update has shown that AT&T is open for pull (the update can be manually pulled down through the Settings menu) for that Lollipop 5.1 upgrade. By the way, Motorola is also expanding the soak test for Verizon today and allowing open pull.
A report from Gotta Be Mobile states that Verizon started a soak test for Moto X Android 5.1 last week, and reportedly finished it over the weekend. This means that Android 5.1 should be available to Moto X users (2014 edition) but this update has been a little slow to roll out. Verizon users of this device are encouraged to check their Settings menu to see if it is available.
I suppose that leaves Sprint and T-Mobile not having the Android 5.1 Lollipop update on their Moto X, 2nd generation phones. This leads to the obvious question of when will Android 5.1 Lollipop arrive on Moto X, 1st generation (2013 edition) smartphones? According to Phone Arena, the retail version of the 2013 Moto X is on its way to the same updates, with David Schuster naming 14 countries now in receipt of the Android 5.1 update. The list includes Austrailia, Hong Kong, India, Kuwait, Malaysia, Oman, Qatar, Saudi Arabia, Singapore, United Arab Emirates, Belgium, Italy, Netherlands, and Spain. In other words, the 1st generation update should be on its way in the United States.
In summary, it looks like the rollout of Android 5.1 on Moto phones is kind of slow, but it looks like it will eventually arrive on both generations of the Moto G, Moto X, and the Moto E "soon", if it hasn't already.