Samsung makes the decision on whether or not one of their phone models will be updated. Verizon Wireless has no say in that particular decision.
I'm most definitely NOT a VZW employee. If a post answered your question, please mark it as the answer.
Yes and No. Samsung makes the decision on which of their devices are updated to the latest OS. Then they release that OS to the carriers to distribute that OS to each of their customers with that device. Usually each carrier then performs tests on that version of the OS to make sure there are no problems or conflicts with their network that will arise for their customers.
For whatever the reason, Verizon has historically been the slowest of all carriers to update Android Operating Systems on their devices.
So any delays in the release of software patches and or OS updates occurring between the initial release by google and the eventual update to the device is a shared responsibility between manufacturer and carrier. For that reason, if you are someone that requires the latest OS or software patch ASAP, you are better off with an unlocked Nexus device direct from google or if you have to have a carrier locked device, stay away from Verizon as a carrier until their track record improves.
Sprint, US Cellular, and T-Mobile have all either announced or released the marshmallow update for the Galaxy Note 4. AT&T and Verizon have remained quiet about any future update. Looks like it's a race to the bottom between AT&T and Verizon to see who is slower at providing their customers with new (well roughly 6 month old) features and security measures to enhance and protect their Mobil experience. I won't be surprised if my Project Fi Nexus phone gets Android N when Verizon Note 4 is still on Lollipop.