When it comes to duality it’s the particles that exhibit wave-like properties individually.

And waves exhibit particle behavior because waves are particles and particles are waves. Light comes in waves. But when we see light it doesn’t mean we are seeing a single light photon.

They seem to think the gravity waves are a property of gravitons.

The article talks about gravitational waves, not gravity waves. It is believed that gravitational radiation is similar to electromagnetic radiation. This would mean that gravitational waves are made up of particles called gravitons. But as the article says, we don’t know that for sure because we haven’t been able to detect gravitons yet.

Gravity waves are completely different from gravitational waves.

https://coco1453.wordpress.com/home/gravity-related-terms/

Gravitational waves are not ‘mechanical waves’. It is thought that gravitational radiation is a lot like electromagnetic radiation. Therefore gravitational waves might work like light waves, and have a particle like light does.

If time didn’t “move” there would still be that single dense area (there was never a point).

No time -> no motion no movement no changes.