Yeah, I don't think something like this should be a thing. They shouldn't need to make more room for future stories by throwing the conclusion to another in a one-shot with a high price tag. That's just poor management if that's the case. I think some instances it's fine like the ASM Sin-Eater one shot, sure, that's a read that's nonessential but for those that want to read it they get more context to the villain of that story. This is the big epic conclusion to a story that's been happening in the main book but now you have to pick up this big extra book to see what happens.
To be honest, I stopped picking up ASM at the end of Last Remains (the main story, not the continuing aftermath smh). Just not really worth it right now to be going out there for this book during the pandemic when things go on forever and they keep pulling stuff like this. I like Spencer's approach, and I like how he's always going meta with it regarding how he knows the readership is feeling but I do think editorial should rein things in and know when to tighten stories instead of going for the absolute maximum with every story. Just cause you're Marvel and you can doesn't mean you should.