I think the waiver will only be for one yearly fee. That does not mean you will get the fee waived next year but frankly for the reductions in benefits due to the merger I doubt many will keep their Barclays mastercards without such an offer. I have two such cards and might keep both if they waive the fees on the anniversary of each.

As an aside, I also have a Citi AAdvantage card which I am going to cancel. I am going to tell Citi the reason I am cancelling is because of their involvement in the reduction of the Barclays' benefits (no more companion certificates and 10,000 eqm's).