It is true, no entirely new features have evolved, ever. I know this as a fact. And, rather than being a denial of evolution, it is one of the strongest evidences against creationism.
Every "new feature" that has evolved is a modification of previously existing features. The bat's wing is not a de novo appearance. The bat's wing is a modification of tetrapod forelimbs which are themselves modified sarcopterygian pectoral fins. An entirely new feature, appearing out of nowhwere, would be an evidence for creationism.
I am going out on a limb to make this claim. It can appear as though complex new features appear suddenly if one separates the lineage by too many years. Hence, if one takes a single-celled paramecium from the Paleozoic and compares it to an aquatic mammalian cetacean from the Cenozoic, it will be obvious that there are new features. However, the features that are "new" on the cetacean are yet modifications of previous adaptations from her ancestors.
This claim seques into the reality that there is such an interconnectedness in life that screams of common ancestry through evolution that I do not see how it can be logically and pragmatically reconciled with creationism. It would not take much to create significant discontinuities in life. For example, a centaur with a equine body and a homind abdomen and head would be discontinious with previous life. Why wouldn't a creater make discontinuities to demonstrate a fingerprint rather than making life so explicable through phylogeny and homologies?