California Air Resources Board this month just issued emissions certifications for 2019 2WD and 4WD Cx-5 with the 2.2 diesel engine. No telling when we might actual see them on the road. It is possible Mazda might announce something during next month's Chicago auto show
https://www.arb.ca.gov/msprog/onroad/cert/pcldtmdv/2019/mazda_ldt_a0160460_2d2_l3-160_diesel.pdf
https://www.arb.ca.gov/msprog/onroad/cert/pcldtmdv/2019/mazda_ldt_a0160460_2d2_l3-160_diesel.pdf