Sure, and then the next day someone said "hey, let's move the entire product architecture at a fundamental chip level in a direction that makes PC-style modularity extremely difficult" and changed course 180 degrees. Or, Apple had been working for years prior to the 7,1 on a transition plan to ARM and knew exactly that they were doing and what they were saying.
The only thing the above is evidence of is a complete lack of imagination. That somehow SOC means you cant have memory or slots. It does not. Same kind of very certain thinking that told us modular couldn't possibly mean slots—which happened to be proven 100% wrong.