As LG fixes a shielding issue with its LG UltraFine 5K Display, Apple is now listing the monitor with a 5-6 week shipping window. Apple has also removed the ability to pick the display up in-store as well.
Prior, the monitor was shipping within 3-5 days in January, and before that the monitor was available to ship in a couple of weeks.
The issue, ultimately, was that the display had a shielding issue which was caused when a Wi-Fi router was placed within close proximity, causing the display to glitch out and freeze. Last week, LG apologized and announced that a fix was on the way.
Going forward, all UltraFine 5K Displays will feature the improved shielding fix, protecting them from potential radio interference with Wi-Fi routers. Any display purchased before February 2017 should be sent in for repair via LG.