I see from your badges your a netapp employee, so you have more resources than I would as a customer. I would check with your sources, but I don't see how it can be a requirement for 8.2.1. I searched the release notes but nothing jumped out at me.
As part of your deployment, no cluster, (unless 22xx) should go without acp. I suggest your customer cable it up as in
Universal SAS and ACP Cabling Guide
It takes a few minutes to setup acp, and then you will not have any issues
ACP is quite simple and doesn't take any time to setup. I believe there is an ACP requirement going forward not to run, but to perform any sort of firmware updates. As an employee, you should be able to determine this quicker than us.