It would be if you were cancelling a Platinum card after opening Gold, which seems to be the pattern that American Express is seeking to change. In any event, there will be targeted exceptions..
I certainly hope that's the case. I held Plat for about 3 years before cancelling and have been waiting for a good SUB before trying Gold (missed out on the referral one). Without SUB, I will never apply to find out whether it would be a good fit.
LAX