I see no problems on leveling the new class, if you being helped by one or two friends on the missing healer or tank roles, so your queue time will be low. On the best, if you have enough friends willing to help, you can make light party straight away and make all run you needs to level up.

The "problem" is that too much players nowadays are lone wolves and does not have enough friends to even make a light party, or have friends that does not have the willing to help each other.

SE cannot do anything on the issue.