Absolutely. High-milage fleets turn over every three years. The Toyota Prius became popular with taxi drivers very rapidly. As soon as the economic advantage is real and large enough, the switchover will be quick.

There will then be a long tail of lower-milage users swapping over gradually, and a small chunk of resisters and nostalgists driving manual petrol vehicles because they like it or have the same "beater" for 20 years and don't want to change.