It doesn't mention test at all in the agreement, I don't know what OP's talking about. It only forbids production installations.
Pretty sure it means you can't have servers running your tests that prepare your production code for deployment. Maybe you use RHEL to run Openshift 3 with containers spinning up a test environment to run acceptance tests exactly like production before deploying the same containers on the production machines. Not allowed with the free dev license.
In my experience, I've always got the dev / test env licences for free anyway when paying for prod / dr.
It's a checkbox in some companies procurement method, in the same way many require source code escrow just to do business.
Maybe they are worried about perpetual beta sites.
If it's externally accessible to customers, it's production. Whether you call your served content beta is irrelevant.