Despite what that article claims, silk bulletproof vests are not new. They were initially invented by a man named Casimir Zeglen over a century ago (WIKIPEDIA LINK HERE).
Recently, the British Royal Armouries have tested a replica of his vest made based on Casimir's patent to determine if it were actually bulletproof (CLICK HERE). Tests show that it could withstand a pistol shot from guns made in that timeframe. I don't know how this new Thai vest compares, but I imagine that the Thai vest would be stronger with the resin and hydraulic compressing that they are using.
As others have stated, this could be a potential application for KBLB's silk to achieve even more protection than the standard silk.