This is quite surprising, considering the prediction back then that 2011 was a weak draft. Outside Kyrie, no player was projected to be an All-Star. Looking at the moment, it looks deeper than 2010 and 2012 class right now.
2011 draft class All-Stars:
Kyrie Irving (1st)
Klay Thompson (11th)
Kawhi Leonard (15th)
Jimmy Buttler (#30th)
Isaiah Thomas (60th)
Now compare it to 2010 and 2012 classes:
2010:
John Wall (1st)
Demarcus Cousins (5th)
Paul George (10th)
2012:
Anthony Davis (1st)
Damian Lillard (6th)
Andre Drummond (9th)
Draymond Green (35th)
That said, 2012 might still look deeper and develop more All-star players as it arguably have a deeper pool of solid players, but then we have borderline All-star in 2011 class that haven't made an all-star appearance yet (Brandon Knight, Kemba Walker, Kenneth Farried)