If they fulfill Nazhun's requirements, Bootstrap and Grandparent paradoxes can no longer exist—the timeline "closes," meaning that anything that's happened in the past has already happened. It's a tighter, more restrained, more restrictive mode of time-travel. I'd look at something like Terminator (the first one) or The Merchant and the Alchemist's Gate as reference for how this works.
It is ironical though, that getting that ending relies on multiverses : Nazhun telling us how many times her work still needs to be looped, and the rule book implying that she might die too early in any remaining loop.
Maybe we then realise then that things did not happend the way we think they did. We really did the actions, but interpreted their context and result wrong🤔