They didn't replace ECAF with another system, they removed base-layer arbitration completely and created the official way to use app-level arbitration. These are two completely different things. Base-layer arbitration means the arbitration of constitutional disputes. With EOS NY's proposal, this would be in the hands of BPs.
I don't agree with your logic. By removing ECAF they are replacing it with something else.
It's the community which sets the rules, not ECAF. ECAF doesn't have any say in the constitution, and it really shouldn't. That's the job for the community. ECAF will only resolve the conflicts that the community asks it to resolve. The constitution is the scope.
The EUA is the exact proposal that will hopefully remove them.
It was a mistake to install a group of under funded, inexperienced volunteers into the constitution in the first place.
BPs can do emergency actions also in the current system. They just need to file a case after that, so that ECAF can verify if the action was rightful or not.
The community will decide if BP actions are rightful or not. We don't need ECAF for that.