I say no, because Danny is a real Celtic and a very good drafter. Time is certainly running out on him to repeat a championship, but I don't see it as his fault.
In my view, more the coaches fault. Stevens has his strengths and weaknesses. His main weakness is he doesn't play bigs who can defend the paint. I've heard the complaint in the media that he didn't put Williams on Bam at critical times. That may have cost them the series against what many view as a weaker team. Charles Barkley doesn't like the Celtics because he says they don't always pass for the best shot (Red Auerbach's dictum), instead at times sitting selfishly on the perimeter bombing 3s. To me, that's the coach. Overly dependent on the 3, and not in complete control.
Danny and Austen seem to have recognized the need for a rim protector, having drafted 3 or bigs the last couple years, but I don't see the coach much complying with their views. I think there's a conflict, and something will have to give.