Amex is kind of sneaky how they post charges to your account
I've had it happen twice now in the short time I've had BCP where charges just BAM immediately hit (usually it takes a couple of days) and that's right at closing time. I even timed it so that I had charges on it the day before closing thinking they wouldn't post but guess what - Amex actually posted the NEXT day so that the charges would hit and did. My BCP said the closing date was the 18th but they actually closed on the 19th and so that charge hit.
I don't really know what the hell the point of playing with that is for these lenders. They seem to want to post a balance. I'm just going to make sure I do not use Amex for a week before they say the cut off date is, and then wait until the day AFTER it actually posts to charge anything if I don't want a balance hitting. They will lose swipes with this game but that's cool by me. I'm not using these cards all that much anyway. I may just let a small recurring charge hit the BCP do the same with the Gold and not really use them other than that. I don't know, still making up my mind, but these games don't make me want to pull my Amex cards out.