Musk did not publicly endorse high resolution radar until recently, and using high resolution radar is not a unique feature of Teslas. Waymo currently has 5 high resolution radars on their cars.
Given what is public now, I'd speculate that perhaps they were working on replacing radar all this time. Then they used vision as an excuse to dump the existing radar early when there was a parts shortage.
I see Musk acting a lot like Jobs in certain ways. They were both very cagey about the future direction of their products. Although Musk didn't exactly backtrack on radar, he wasn't transparent about Tesla's plans either. You don't telegraph your moves to your competitors. Similarly, I'd be very surprised if Tesla wasn't keeping an eye out for lidar crossing a specific cost/function threshold. They're not saying that aloud, though.
