I filled in the form on Delta's website and attached a screenshot of my status from Scandinavian Airlines' EuroBonus page.
A couple of days later I recieved the following email from ContactUs.Delta@delta.com
You are now enrolled in the SkyMiles Elite Match Challenge. Your temporary Medallion status will be effective on November 3, 2017. Please look for the terms of your 90 day offer to be sent to the e-mail address in your SkyMiles account. If you have any questions, please reply to this e-mail only.
We appreciate your interest in our Medallion program, and look forward to proving ourselves as your airline of choice.