I am sorry, but megapixels do not a good camera make.
My Fuji X100 (35mm prime) and Nikon D200 (50mm prime), the latter from over a decade ago, both easily produce clear pictures in eye reflections when the light is good.
That said -- have you actually tried?
I just took a selfie with my MotoG5s front camera, and I can see a face from my FB feed reflected in my eye. And that's in crappy office lighting, from a screen with brightness turned down to minimize strain!
>Or even any staged photo you have or can take
To re-iterate: it is ridiculously easy to take such a photo with a real camera with decent lens. Modern cell phone cameras are capable as well if the light is good.
Here's a non-attempt: just a crop from the selfie I took
You can't, because the information isn't there. The same way you can't read a book that is closed, even with a super computer.
But resolution is limited.
If you are so sure it's "obvious" you can extract recognisable faces from reflections on photographs containing eyes - show me you can do it using any photo containing a headshot you can find on Google Images or Flickr... Or even any staged photo you have or can take - showing enough resolution from a headshot that you can extract recognisable faces from eye reflections. I have a 12 megapixel camera in my phone - and I'm not convinced I could reliably take a photo of someone's face with enough resolution to pick to recognisable detail in a reflected face in an eyeball...