No, as long as the shutter travels evenly it should be fine to use. If the wrinkles are really bad, it could hurt the resale value, but it's unusual to find a 7-series camera that doesn't have at least one or two shallow wrinkles or pinpoint dents.
If it gives you any perspective, reflect that these wrinkles are often caused by localized heat of the sun being focused on the curtain, and that when the same thing happens to a cloth-shutter camera (e.g. a Leica) you don't just get a wrinkle, you get a burn hole.
Incidentally, the metal curtains came in during the run of Canon's V-series models; earlier ones (II, III and IV-series, and early V-series) did have cloth curtains, so your impression is correct. Just to make this a bit more complicated, during the era when factory service was available for these models, it wasn't unusual for a cloth-curtain V-series camera sent in for shutter repairs to have its curtains replaced with metal ones. Conversely, an independent repairperson might have replaced a hopeless set of metal curtains with cloth. So don't get too weirded out if you ever encounter a model that "should" have cloth curtains but has metal, or vice-versa.
