I noticed recently when playing around with the BMW USA configurator, it was no longer giving options for the 6-Series coupe, only the convertible and grand coupe. I thought this was odd, but now
according to Road & Track, BMW stopped building the coupe back in February.
This is probably going to be a one-off situation for the 2018 model year, because when 2019 comes around, BMW will sell the 8-Series coupe (or whatever they end up calling it).