That's odd. I could swear I'm paying for an MSDN "test engineer" account just so I can download and install MS server ware without having to jump through extra hoops for activation and stay legal for licensing (that's what my corporate counsel told me I had to do, no eval versions allowed).
Frankly my Linux strategy for SQL Server 2016 is Postgres. The trick is not to need any serious disk i/o performance, hahah.
MSDN and EA licensing are completely different. If you’ve never worked under an Enterprise Agreement, I can’t speak for your arrangement. Having worked in this capacity for 4 corporations over the last 15 years, I can tell you that this is pretty common for larger EAs.
Also consider if you’re using MAK (Multi-Access Key) licensing vs. KMS (Key Management System) licensing, that makes a huge difference. We are afforded a large number of MAKs each renewal, but most of our licensing is done through volume licensing in our KMS environment.