https://www.theverge.com/circuitbreaker/2018/8/14/17689028/sprint-lg-5g-smartphone-early-2019-announcement-mobile-networking

Sprint has announced that it will work with LG to release a 5G smartphone for Sprint’s nascent next-gen network sometime in the first half of 2019.

There are no concrete details for the device other than the vague release date and the fact that LG will be making it. But since the company plans to launch its 5G network (at least in part) in 2019, it makes sense that it would put deals in place for the devices that will support it when it rolls out.