There's been a bunch of news posts on various sites today station that BMW has discontinued the range extender option for 2019 along with adding a larger battery which is now 42 kWh. The larger battery is true, and it should increase the EPA rated range to about 150 miles per charge.
As for the range extender, yes, it has been discontinued in Europe because of stricter emission regulations. However, it will still be available in North America as an option as it always has been. I have this directly from the top BMW NA communications manager.