Well, except for the iPhone 5/iPad Pro 2-esque squared off sides.
It wouldn't be surprising if Apple has been toying with a return to this style for a while though. No doubt by the time of the iPhone 8 they were aware that the 6/6S/7 style was starting to look tired.
Renders are typically ‘fan made’ art. There’s not one source back in 2017 that would know the finalized design for the iPhone 12 moving forward into 2020. Not even Ming Kuo would have _any_ idea of what that phone would specifically look like three years in advance. Not to mention, apples finalize designs are typically completed a year before they launch.
So for example:
when the iPhone 11 launched in September 2019, Tim Cook and company already knew what iPhone 12 final design/schematic will represent for 2020.