I made this same mistake in June with my Bonvoy Boundless, transferred all but $500 of my credit line to another card since that was the max I was told I could move over. I intended to get the 5 night offer for the Boundless, was still denied because I have the old SPG Amex card, and wasn't going to close two cards. So I tried to reinstate the account with maybe half a dozen people, including working with two different account specialists at two different branches I know to think of a way to reopen, and no luck. The Bonvoy card requires a $5K limit, and was told if I left $5K on it and closed it, then I likely could have reopened since I was inside the 30 day window. Otherwise that 9 year old card is history, which is the case now.