My name is James. I wrote that letter with LiS spoilers. The moment Rob acknowledged the spoilers, an incredible sense of dread poured over me. Up until the moment I heard him thank me for spoiler warnings, I hadn't even realized what I'd done. The whole letter was a sort of emotional release for me and I didn't do much thinking. I deeply apologize to you and everyone else I spoiled on a game I think is so beautiful.
I hope you either have or will still play it. The narrative conceit is truly the vessel, not the end goal of LiS in my opinion and I think you might still be able to experience its most important messages and moments. Happy gaming.