Mazda are doing this now with their new MX30, if it proves successful then others will adopt but the process is slow to produce a new car.
I don’t believe Mazda’s incarnation will prove much other than Nissans E-Power is a far superior set up, even though both use the same principle, using the engine as a generator only.
The spec’s are agains’t Mazda:
The MX-30 e-Skyactiv R-EV needs 9.1 seconds to perform the 0 to 100 km/h (62 mph) sprint and is electronically capped at 140 km/h (87 mph) and will achieve around 29 mpg.
I can’t remember if it was honda or another manufacturer who came out with a similar idea to Nissans E-Power first, but, the E-power is unique engine wise if you look at the specs on the QQ thread.