From what I have read/watched from "leaks" I think it is 09:00 a.m. EST = same time as Performance Benchmarks Embargo lifts.
I think you should look on newegg.com and amazon.com around that time.
Just on a side note, the manufacturers are offering different warranties. Sapphire only offers 2 years on the Vega 64, as does XFX and Powercolor. Gigabyte and MSI offer 3 year warranties according to the information on Newegg. That's kind of a big selling point to me.
Lots of Reviewers complaining they have been very pushed for time after Threadripper now Vega 56 and 64 and saying their reviews need more work ... but but here are the reviews I found ...
AMD Radeon RX Vega 64 performance preview • Eurogamer.net
I will keep looking.
The Liquid Vega 64 is not on sale here yet so far.
I stand corrected ... The Vega 64 Liquid, Limited, and Black Edition are now available.
Now its time for me to read the reviews and convince myself I really need a Vega Liquid 64 Bundle Pack .... .
One thing I still wait for is the latest version of the Vega FE Drivers and reviews, they still have not released the updated Vega FE
I will keep looking for more reviews.