According to Australia’s Motoring website that could be the case:

Speaking at the international launch of the all-new F80/82 M3 and M4 in Portugal over the weekend, BMW M Division Head of Product Management Carsten Pries told motoring.com.au it was “foreseeable” that a four-cylinder engine could power the next generation of the iconic model.

“We do not start our design process with a power output in mind. We have a set of characteristics that a new model must meet. For sure, you could see a future [M3] powered by a four-cylinder engine,” Pries told motoring.com.au.

“Performance can be boosted with more power, but if we are to address issues like emissions and consumption [in the future], we have to look more at weight. We decided in this generation to address the [upward] weight spiral,” Pries explained

Pries said the downsizing trend is likely to continue in future generations.

“If we have a car with less mass, it is foreseeable that the [performance] targets we set could be reached with a four [cylinder],” he stated.

It’s a fascinating idea. Going back to a bespoke four cylinder engine with likely more that 430 hp sounds pretty interesting to us. It’s only too bad that the M2 won’t be able to take advantage of this approach as that would seemingly be the perfect package for such an engine.