It is not enough.
While a large improvement, those are some chunky looking glasses that I do not imagine anyone wants on their face.
These things look at least twice the thickness of anything I'd ever consider wearing in public, in any circumstance.
That is literally the opposite of what Meta is saying. In fact they aren't even releasing this pair because they know it's too chunky.
Without relying on a tether, there's only so much you can do. You have to put some compute, battery, and optics somewhere. The optics in particular will always be fairly large just due to the physics of light and lenses.
The only way I can see us sidestepping these problems is by putting the optics somewhere else and using a fiber optic tether. Even then, you still need some optics in the glasses to project onto the display lenses.
Maybe someone will figure out how to do a transparent OLED display on the lenses directly. Even then, you've cut the bulk required for optics but you still need somewhere to put the electronics. A tether is really the only way to go if your concern is form factor.
You realize this is a prototype and not available for sale to the general public... right?