Julius Onah discusses the look of the MCU villain: "You want to make sure that even with these heightened characters, it fits into the world of the film."

I am absolutely certain that the Leader’s distinctive cranium underwent a significant redesign in rehoots, and early character designs support this.

While the MCU's perpetual merch spoilers aren't a great part of the franchise's traditions, this is one time fans might actually have preferred it.