Well, he also believes the EyeQ4 can achieve L4, which even Mobileye does not:
https://www.mobileye.com/wp-content/uploads/2016/11/Mobileye_EyeQ_Infographic6-002.pdf
And as @Vitold pointed out, EyeQ4 was late. So, maybe Elon learned from Mobileye on product timelines?