Leaks have a high chance, especially for a highly anticipated title like Pokemon. And banwaves are 100% happening again, so even if you turn off data sharing to Nintendo, you'll most likely still get banned as long as you used in-game online features before November 17. Since USUM are indeed coming simultaneously worldwide without exceptions, I feel the chance of getting it early is more likely.
Here's the code for compatibility with Gen VII
7 GB placeholders RGBYGSC... so I feel like Crystal is coming, but GF decided not to coincide it with GS, mainly because It would overshadow sales of its predecessors, or maybe it has something to do with an in-game event for Celebi exclusive to it? I dunno, probably the former.
It was 10-11 days prior to the 18th. I clearly remember the US elections craze going on as well as the Moon leak happening via a vp user who also teased his game screenshots. Sun followed in a few days, dunno when though.