Just to follow up, I put in a retail CD KEY and got the trial restrictions lifted along with the extra play time of the trial added to the 30days play time. So atm I have 35 days left. So it is confirmed.

Play the trial

You get 7 days free play time

Add a Retail CDKEY get +30 days

37Days total play time without restrictions.

I know World of Warcraft allowed you to upgrade on a trial and keep the trial time while removing restrictions... Is it the same here?

If I put in a retail CD key will I keep the 7 days of trial time +30days of game time without trial restrictions?