I don’t think any content should be locked up for a game. Case and point the specializations. That should have been available from the start.
Now for people who bought the LE, I would be down with them getting special armor to show that they bought the LE. I would like that armor to be unlock able to other players after some trials and tribulations.
However, I don’t think half your game should be locked up because you didn’t shell out enough money for example. If you develop new content, thats fine people can pay for that. But don’t have people buy what is essential half a game.