This transition time makes all the model naming a bit awkward ...
How will BMW model designations look like in 20 years from now, when the last ICE has died? We are still taking 320, 340, 530, ...?
I think there is no need to maintain the traditional nomenclature. It is a new era in parallel with the current one, so time to build up a new image. The is no relation between both. There can be some exceptions like M badge, 911, Mustang or some iconic names, but it is the minority and not an issue at BMW, Audi or Mercedes. Even the S Class is dead.