i just read the Q&A from Live letter

Q: When randomly choosing content through the Duty Finder you said that the rewards will become significantly better, but exactly what kind of rewards get better?
A: We plan on implementing this system in patch 2.1 when we add dungeons for level 50 characters.

so no lv50 dungeons?????? all this awesome dungeons shown in dungeon crawler p2 are up until lv49? SE is kidding me right?