At this point, there is very little we don't know about the upcoming LG G6. It will most likely have a Snapdragon 821 CPU (due to Samsung claiming the entire initial supply of Snapdragon 835 for the Galaxy S8), a 5.7" display, and ship with Google Assistant. It won't have a removable battery either - LG wanted the phone to be water-resistant instead.
Now the launch date itself has been revealed to be April 7 in the United States, with South Korea sales starting on March 9. This gives the G6 two weeks until the rumored Galaxy S8 launch - April 21. Perhaps that short period will be enough to get some momentum going before the S8 hits store shelves.
With the LG G5 being somewhat of a failure, especially with regards to the modular functionality, the company needs a hit with the G6. We will have to wait and see if LG can deliver.