With the sales of sedans continuing to go down, I think Lexus realizes that they have to get rid of one of their sedans.
My guess is Lexus management sees their sedans shaping up like this:
IS: Grow the next gen for better interior space, will have same engine options as the GS would have(return of IS F) Personally, I believe the compact sedans are more important then the midsize cars, and without the GS it will be easier to add more luxury and amenities to the IS. This is their BMW fighter
ES: Mid Size option, more comfort then sport, but possibly add AWD option. It's worth pointing out that Audi's are all FWD with a AWD option, and Toyota seems pretty proud of the handling of the new global platform which the ES will go on. This is their Audi fighter
LS: Obviously flagship sedan, probably feels sales will improve if the GS option is taken away. This is their Mercedes fighter
My guess is Lexus management sees their sedans shaping up like this:
IS: Grow the next gen for better interior space, will have same engine options as the GS would have(return of IS F) Personally, I believe the compact sedans are more important then the midsize cars, and without the GS it will be easier to add more luxury and amenities to the IS. This is their BMW fighter
ES: Mid Size option, more comfort then sport, but possibly add AWD option. It's worth pointing out that Audi's are all FWD with a AWD option, and Toyota seems pretty proud of the handling of the new global platform which the ES will go on. This is their Audi fighter
LS: Obviously flagship sedan, probably feels sales will improve if the GS option is taken away. This is their Mercedes fighter