I cannot see it at all. It's going to be at least LG UltraFine 27" money
With emphasis on the “at least”.
The LG 5K has a mixed reputation. Yes, 5K at 27” makes for an excellent retina experience (like the iMac), and that is its primary value proposition, but in almost every other respect it’s a fairly mediocre product. The stand is poor, the materials feel cheap, the design is arguably unattractive, and some people have had image retention or other issues. So I think if Apple were to release another screen, it would have to be a substantially better product than the LG… and that will come at a substantially higher price.