The root cause does not appear (at this stage) to be the same: incorrect maintenance in AA191 as opposed to fatigue cracking here.

Where does this report say proper maintenance would have prevented the incident?

The report doesn't say that because it's just reporting the facts not drawing conclusions. In my opinion, if a catastrophic failure happens that is a maintenance failure. Either the inspections failed to notice the fatigue or the inspection guidelines were too optimistic.

AA-191 was caused by improper maintenance (dreamed up by people who were made to cut corners and was never compliant with manufacturer spec) damaging the pylons holding the engine.

If someone did the same thing again, that would be rather unfortunate. Just more deaths for profit, even though we know it was dangerous.

The parts that seem to have fatigued and failed were only like 80% of the way through their inspection period. They were to be inspected after 28k cycles. They were at 21k cycles.

It sure looks the same from "Engine pulled itself off and flew away" angle, but if there is any similarity under the surface that's very bad. Flying was much much less safe in the 70s.