“It’s possible for an event in the present to alter an entangled event that occurred in the past.”
That’s simply wrong. Nothing that happens now can change a reality that has already occurred. You can only update something that has already happened. And has never been proven to have done so.
Multiple quantum entanglement experiments have shown it is possible to alter the past. Quantum scientists know it can be done because they've done it. The past, present, and future occur simultaneously. What we sense as time is an illusion of some kind.