It's not that you can run G-Sync without a module. The interesting thing is written here:
"Here's the facts: NVIDIA will release G-Sync on mobile devices without the requirement of a G-Sync module, but the company claims that there will be experience differences between desktop and mobile iterations of the technology. "
I have no idea what to make of it. Mobile G-Sync will be something like FreeSync (cause both don't require the module) but on normal monitors the G-Sync module is something that improves "Adaptive Sync"? I wrote it that way cause we know that Adaptive-Sync works through DP 1.2a while G-Sync monitors only use DP 1.2.