Well that has only been for a few hours.
This is not solid and legit data, sorry.
I only use rock solid data for my analysis!
I cannot confirm this prooves that they have decoupled.
Right now we´re back to the ususal 20$ price difference.

chinese exchanges might dip pretty low, for a moment, but stamps will not follow, then all chinese exchanges should start to see demarictly less volume, and have price stabilize near stamps price.

thats my best guess