Very unlikely. In frame batteries are far too small very often, Cytronex 162 Wh, Powabyke X-bike 234 Wh, Bosch 288 Wh. Even rack batteries can be a bit too small for many. The great advantage of the rear of seatpost setup is having batteries up to 740 Wh, yet with the weight sitting low down, roughly central between the wheels with a slight rear wheel bias which is preferable for handling. As the Panasonic unit bikes show, they don't have to stick out above the frame, even with very large capacities up to 624 Wh, and some of them can look stylish too.
You mention cars, but desirable car styling once included long bonnets and a powerful image, and a glimpse then at some of today's snub bonnet bulky passenger compartment cars would have caused derision. This shows that people can get used to the practical and eventually regard it as stylish.
E-bikes are too rare and not used widely enough for this to happen at present, but if they ever become de rigeur, practicality will win out eventually and be regarded as style.
And handlebars? There will always be comfort bars, and as the Netherlands show, the more cycling and e-biking there is, the more that comfort bars are used.