Creative Cloud discount for old members

No.  Offers like this are intended for new customers that have not subscribed to the Cloud previously - an incentive to draw new people in.

You would have to become a new customer, abandoning your current account...  which would mean canceling your current subscription (if any) unless you still want to pay for it... cancelling early will result in a penalty of 1/2 the remaining cost.

Of course, you can always contact Adobe Support (these forums are not them) and see if they would be willing to grant you some benefit from this new discount.

Creative Cloud support (all Creative Cloud customer service issues)

https://helpx.adobe.com/contact.html?step=CCSN_membership-account-payment_change-or-upgrade-your-membership