I am not sure why he should not have done, unless he actively interceded in CNN's own coverage.
People have to be permitted to be humans. He clearly disclosed his involvement at the time, so there was no failure of candour. If CNN was concerned, it should have put him on hiatus.
There's a whole load of wisdom in hindsight here. And then there's AG Letitia James, whose own political ambitions are involved and which were not properly revealed.