Yes. 16 or 32 GB it's a matter of physical space.Bigger phone has more hardware. No duh. Big deal.
This is like people expecting a huge V8 engine in a subcompact car.
You can't expect a sub compact car to have an engine as large as a full sized car.
Same with phones. A large phone just has way more room to put more hardware.
iPhone 7 Pro - 5.5 inch screen, 32GB, dual camera's $750
iPhone 7 - 4.7 inch, 16 GB, single camera $650
I see no problem with this lineup