What could he have done? Sued? Given it was all completely true? It's exactly what City should have done and didn't do. It's exactly what lots of clubs could have done and didn't do. This won't be just about City, it'll be about lots of different clubs turning a blind eye to what went on. City are high profile, and with a high profile comes a fully deserved focus on what the club did so wrong back then.
The current club can't undo what happened then, any more than anyone else can. What they can do is everything they possibly can to be open and honest, and compensate people as best they can, irrespective of what it costs, and irrespective of what damage further revelations might do to them. No alternative, not morally, and not even from (hideous though it is) a PR perspective.
Total disclosure where legally possible, and total acknowledgement of their responsibility for it. No excuses.