While they would be compatible, there is no demand for smaller HDMI connectors in the marketplace. There are very few people who would benefit from the smaller connector. Those who fish HDMI cables down conduit would but other than that. There is plenty of room on the back of AVRs for HDMI connections.
I supposed when we want 10-15 HDMI inputs on the back of an AVR, then there would be a demand. But, the bottom line answer is plenty of supply of the Type A and little demand for the Type D.