You're all collectively agreeing that you believe the same things and will never consider anything different.
Good job.
Note: imagine arguing against possibilities existing
There's being open to possibilities, and then there's believing in random bullshit simply because you've personally constructed a justification for it, even when that justification requires you to ignore what the story itself has already shown.
Here's a sentence that speaks your language: retroactively finding thematic compatibility is not the same thing as the story having actually set something up. The Nika bullshit is still a retcon, no matter how much reverse-engineering you do on the text trying to defend Oda's decision to no longer give a fuck about his own in-universe coherence.
Also, the mere existence of infinite possibilities isn't inherently a positive thing, either.
Take your example with Shanks from the other day.
Shanks being a morally gray character would've worked better, than that possibility-cum-reality that is him having an evil twin. That's a soap opera b-plot. Just because it's possible, it doesn't make it qualitatively good.
What was already established - Shanks working for the balance of powers; him trying to keep WB from engaging in a conflict; Sengoku respecting him - narratively weighed more than introducing a brand-new character clone that can do anything Shanks can, only on the other side of the barricade. That's not an entertaining possibility: that's lazy writing.