Is it true that if you cancel your BA Visa, you maintain all of your BA miles and rewards (such as companion voucher)?

I don't use my BA Visa anymore, and have been holding onto it since I haven't used my 100k+ miles and rewards, but if I keep blue membership status with the executive club and can still use my rewards with my credit card, I plan to cancel it before paying a 2nd $75 fee.

Anyone have a reason not to cancel this card? (other than the regular penalties of canceling a card affecting your general credit)