One of the things that doesn't seem to be stated clearly here is that Good (in a multiverse where Muscular Neutrality is Actually True) needn't be invested in the continuation of life in order to respect and value it.
It's Nirvana. It's the Rapture. It's the end of the world as we know it, and everyone is fine. Every story comes to an end, and the story of life can come to a good ending.
This isn't secretly evil or monstrous or anything. If the premise is that Muscular Neutrality is Actually True, and people are aware that this is how the cosmos works, it's just what you want as someone who values and respects life. For it to end happily. Heck, Good is altruistic and self-sacrificing - Good is OK with the idea of ending life in service to something greater. And, in that multiverse, if everyone was Good, they'd all be OK with the idea of their lives ending to prevent any suffering from happening again.
Life itself is monstrous. Living beings are worthy of respect, but as a consequence of " Muscular Neutrality is Actually True," life mandates that disrespect exist if it is to exist. It's a blessing to feel the soft spring rain on your face, but if that blessing means a trade-off with a drought-stricken nation devolving into murder and exploitation, then it's not really much of a blessing after all. To honor the living can mean to usher them softly into being non-living.
This kind of Good can be antagonistic, still. If the premise is that Muscular Neutrality is Actually True, we'd expect some "heroes of neutrality" who fight to keep the multiverse alive (and screaming). It's an understandable position from sort of a base animal perspective. The survival instinct is strong. And like, reality is where you keep all your stuff, so if it ended, what, you'd have nor more stuff?! So of course these Champions of the Status Quo, these Radical Centrists, would fight off the thing that could solve everyone's problems. They would not be Good for it, but that's kind of the point. And, of course, this kind of premise makes excellent use of tropes like overly-zealous angels and well-meaning idiots. Ascetic codes like chastity and dietary restrictions can make more sense in this world (don't make more people - they'll just suffer; don't kill animals to eat, that's unnecessary suffering). But antagonism doesn't mean evil in this case. Wanting to bring everyone eternal peace isn't evil, even if it would mean the end of life.
Every story comes to an end. The story of life is no different. It is not monstrous to accept that one day we all must die, and one day, the dead spheres of frozen rock that used to be our planets and our suns will be the last blind witnesses to a dead universe, cold and dark, without any living creature in it, incapable of having life once again. It isn't wicked to believe that nothing is permanent, including the chain of life itself. Indeed, sustaining life beyond its bounds can be wicked, can make more suffering.
I mean, this is also essentially the big decision in Dark Souls. Probably not coincidentally, from a place where Buddhism is a lot more popular, since some of these ideas are VERY Buddhist-coded. "Life requires suffering" is basically the first of the Four Noble Truths, and is also what a universe operating on Muscular Neutrality adheres to.