So, let me put it this way. Lollipop was released in November of 2014. I had a Sony Xperia Z2 Tablet Verizon edition. Sony released a Lollipop update for the Sony Xperia Z2 tablet in March of this year. The Verizon version is on the list for the update but as of the middle of September when I traded it in we still had not received the update. That was more than 6 months after the release of the software for the tablet which was more than 5 months after the release of the new Android version.
From what I can tell it takes Verizon about 6 months to verify updates. That may be because they find errors and those have to be fixed. I have not seen it take less than that. So when we would get the update would depend on how quickly Samsung got on reworking the Marshmallow source code to the phone and their unique additions and how many defects Verizon finds when they do their intense QA, and how long it takes for Verizon to add in their unique additions and subtractions with their own developers and agreements with bloatware providers.
The simple answer is that most likely you will be asking where the Nutella update is before you ever get Marshmallow.
