"I found this really cool prediction for chapter 693 on mangaspoiler.com"
You were dropping off a text from a spoiler site.
Outside of the 693 spoiler thread.
That had long involved blocks of text that looked like spoiler dialogue translation text.
You were leaking a spoiler.
That it ended up being made up is beside the point.
Look at it from this angle.
"Hey, I read this spoiler, but I'm going to assume its not a spoiler but just an idea I made up or found… but if it happens to line up with the actual thing I seem clever or like I had the inside scoop."
We've had plenty of that in the past. The way you announced your post and the format it took is what looked like a spoiler leak. I'm not even the one that gave you an infraction, and I doubt the one that did looked all that closely, but it IS what it looks, smells and feels like.
What if it hadn't been a made up theory, but an actual spoiler from, you know, A SPOILER SITE.
Which happens.
Its a minor infraction, it's invisible to anyone but you. and the actual post and the responses to it are deleted now. Take it as the warning it's meant to be and don't do it like that again. Keep it in the right place, or present the info differently. But don't brag about finding something from a spoiler site and then post it as an impressive find in the wrong place, and then be surprised when someone thinks you're talking about a spoiler!