It didn’t get skipped. It was a business n marketing decision.
66 was the debut of the Big Block 396/325hp as the base engine in their Chevelle SS. They couldn’t very well promote this new SS 396 and yet have a MALIBU with a small block 327 and 350hp. They left that to their Nova and Chevy II.
Once the hype of the 66 SS was over and the 67 model year began., it seemed OK to have both. A 67 Chevelle SS with a base engine 396/325hp and it’s younger sister 67 Malibu with 327/350hp
But. Indeed…. This car should have been built and here it is…. KINDA