Apple pricing strategy was disappointing last year: starting with a 16GB model allows them to 1) get higher profit margins and also 2) tempt/force people to avoid the 16GB and get the more expensive 64GB model.
The story is about to repeat itself next week: according to trusted sources, the new iPhones will also start with 16GB configuration, even with a camera that will reportedly be able to record 4K video.
Good luck storing that on your 16GB iPhone 6S, pal. Fortunately, we all have 5GB of free storage on iCloud. You can pay if you want more (20GB for $0.99/month), so, basically, problem solved.
For Apple. Not for you.
Source: Apple Event: New Apple Watch bands, 16GB iPhones confirmed with 7000 series aluminum | 9to5Mac