The timing fits. I can't prove it, but I believe it is a great possibility.
Let's start with the propaganda:
Zcash cheaper than Bitcoin to buy drugs on Alphabay
It gets listed:
Alphabay will accept Zcash starting July 1st, 2017
And 5 days later, down goes the ship:
Alphabay is currently down (megathread)
Additional reading:
On Fungibility, Bitcoin, Monero and why ZCash is a bad idea.
Wake up use X-M-R