Another possibility is that August 31st will see Nvidia launch its Ampere series of Quadro products, mirroring Nvidia's Turing reveal. With Turing, Nvidia revealed its Quadro RTX product line before its Geforce equivalents. and the same could hold true for Ampere. For now, all we can do is wait for August 31st.
Thankfully that seems unlikely, NVIDIA's GeForce accounts were hyping the countdown and it's unlikely they would be using many of them for Quadro products.
As someone on Reddit pointed out:
"256(Geforce 256) x 21(days) = 5376
Which is the exact rumored spec of the full fat GA102."
Though, it wouldn't surprise me if Jenson picked Aug 31st just because nearly all the rumors have been saying Sept/Oct for the past year...