I thought so. I was pretty sure he was never mentioned in TDKR.
I get the beef with it, It annoyed me too. But the problem is..... If ledger wasnt dead, TDKR wouldnt be this film. Joker wouldve returned, it wouldnt have been an 8 year gap, and it wouldnt be asif joker never existed.
You can tell Nolan wanted the Joker to return; 'Were destined to do this for a long time','you complete me', 'You wont kill me because of some misplaced sense of self-righteousness, i wont kill you because your too much fun'. It was every batfans wet dream, because it was so faithful to the source material, Ledger nailed a fantastic interpretation of the Joker and it was set up for future appearances.
But Ledger died, Nolan refused to acknowledge Joker out of respect for Heath even if it did feel abit out of place in TDKR.
But I dont let that affect me view on the film, because I understand why Nolan chose not to have any mention of the joker. Probably in the same way you people dont want to give that animal who killed those people at the cinema the time of day or mention him because he isnt worth it; Thats how I look at what Bruce and Alfred are like in the film; You can see the hate but they never mention him. You see the exchange of words between Bruce and Alfred, when he is talking about rachel you can see he is talking about joker. Bruce doesnt need to talk or mention Joker because the scars he carries speak volumes; because of him he was stabbed, because of him he was shot by Dent, because of him Dent died, because of him batman was a criminal as he turned Dent, because of him, his one love is dead and he cant move on. Joker did a huge amount of damage to Bruce, without needing to say his name.
Which is why I can accept it really.