If you can choose your own versions and care at all about new releases, you can track latest and greatest with at the very most a few months of lag. Six months of "support" is luxurious in this scenario.
If you can't choose your own versions, you are most likely stuck on some sort of LTS Linux and will need to make do with what they provide. In that case three years is a cruel joke, because almost everything will be more than three years old when it is first deployed in your environment.