I called and was transferred to Membership Rewards from the Travel representative. I mentioned the code and the rep immediately said she would note my account to give me the additional 50k, but that I would have to call back after the initial 50k post to have the additional points credited (she said she couldn't put the points in immediately). She assured me that it was noted in my account and that when I call back it will be seen and credited.
I'm a little nervous as I would obviously prefer the points now, but I think it should work.