The Membership Rewards terms are published here:

http://www.membershiprewards.com/cat...rmsSplash.aspx

If for any reason we cancel any Linked Account (including because of your death, bankruptcy or insolvency), any points accrued in your program account will be forfeited. If we reinstate the Linked Account(s) within one year of cancellation, any points accrued in your program account may be converted into a participating Frequent Customer program or redeemed for a reward, provided all other conditions set forth herein have been met.

Anything is negotiable, but if more than one year has elapsed since the account cancellation I doubt you will succeed.