Apple Inc. has sold some 160,000 to 180,000 Vision Pro headsets since the device became available for preorder Friday, but a prominent Apple watcher notes that the product still remains “niche.” Ming-Chi Kuo, an analyst at TF International Securities, wrote overnight that investors may be left with a “positive” read from Apple’s AAPL, +1.91% initial sellout of Vision Pro mixed-reality devices, which could be gauged by their extended delivery times shortly after the order window opened. But he also said ...