Everything you wanted to know about the Saudi Abaya and were afraid to ask is here in a Washington Post article penned by a Saudi woman herself.
Ok, granted, women exercise their agency and don't just follow rules like dumb beasts, they resist patriarchy even when they don't consciously intend to, and they manipulate the Abaya to make it more individualistic. Some even rebel and wear a brown Abaya instead of a black one.
But to be honest with you, and I know some will not like this, I can't really get too overworked about all this rebellion.
Only when a Saudi woman walks down the street in Riyad without an Abaya and is neither arrested nor molested, I'd get excited about "subversive" Abaya stories. Only when the Saudi Abaya is no longer a story it becomes news worthy.
All else sounds like Abaya propaganda.