No. If you think about how Constant Image Height projection works, you should be able to see the flaw in your logic.
If the content is encoded with a vertical stretch inherent in the video transfer, you'll still need an anamorphic lens to horizontally stretch the image back to proper geometric proportions. In fact, the lens will become necessary. Such discs will not work with the Zoom Method of CIH.
The only thing true anamorphic Blu-rays would eliminate is the need for v-stretch scaling in Blu-ray players, projectors or external video processors.