Congratulations op. Quite a rare spectacle. Life changing amount indeed for the majority. I advise using it smartly with a long term perspective.
What wonders me is why a KYC check is done here?
KYC checks are usually done whenever users win big, abnormal errors etc and this is usually specified in their T&C.
I wouldn't worry about it since submitting KYC isn't a big deal especially when you win such humongous amounts.