I think it is a bit overwrought, one Admiral leaving early isn't going to be the end of Navy Nuclear Power as we know it.
It won't be the end but I do feel some of what he is saying, the 8 year term prevents the "what is this guy looking for" growing pains from occurring every few years, and given the 8 year rotation they have a good idea about who the next guy will be well in advance, the people now in play for NR are those that until a few weeks ago never had a shot, it will be interesting to see who ends up taking the NR position.
I do find it interesting how he talks about Rickover the way he does considering he is the one that essentially pushed him out the door.
I feel that Admiral Richardson will do a good job.