Touchscreens will be supported. However, the Product was designed with the presence of discrete physical buttons as an assumption, therefore a touchscreen cannot completely replace physical buttons.
Yeah, looking back on stuff like this is fun. Like when we look back in 2014 at the iPad5, which will run on OSX instead of iOS, we’ll chuckle at how Apple CEO Tim Cook said:
…the problem is that products are about trade-offs, and you begin to make trade-offs to the point where what you have left at the end of the day doesn’t please anyone.