I don't know what do you expect from an Arduino board to be considered open
I observed a child asking for an atmega328p, a 16Mhz xtal, breadboard etc in an electronics store, i gave that kid an ftdi adapter i had on me.
They went home, and i'm speculating, they built an Arduino.
In 199X i saved for 8051 mcu development board, which cost lots, i had to borrow books i could not afford, & the only support was subscriptions or letter replies. Because of lack of community, and understanding, the 8051 went into the too hard basket. Later on, Parallax released the Basic Stamp, It was a very exciting time (so i remember) just around the corner was Microchips 16F pic, i have in possession various dev boards dating back to 1989, lots of literature covering, hex, assembler, opcodes. These boards were expensive, lacked free software & lacked community (Exception to Microchip).
Arduino is the 1st 8bit micro-ecology to address, cost, understanding & openness.
The future of Arduino is clearly "more power to do more complex things"
Quite the opposite.
I once knew a man who encoded rocket trajectories & simulations in binary, he confessed that he was taught by a man that knew assembler. His son grew up to code in C/C++, i guess his father didn't teach him?
I was 14/15 & excited to see a program this person wrote, & having been there when his father added "You could have done that in less than 10 lines & not 100".
This is not the best example i know!
The hardware has been there for 30 years, every renaissance period of the 8bit mcu.
It's not the hardware, its the code & the way in which it is utilized to manipulate the hardware.
The future of Arduino clearly "is to do more with less"