I wonder what the lag is like. I can imagine that's one thing that would break the illusion. I know with something like Zoom I've gotten used to managing the lag over time by taking turns with the other person. However, with the "live" feel of this, there could be an uncanny valley effect if the lag is subtle, but perceptible.
Another thought: this is being presented as ongoing research. I wonder what the corporate thinking is in presenting it now when it's still being tried out. Does Google want capitalize on remote meetings while it's still hot? If the pandemic wanes and we have more in-person meetings, this might not make as big a splash. I remember when I worked at Microsoft, I often noticed research announcements we'd make in public often wouldn't translate to actual product, so I got a bit jaded on any cool new thing that was announced without a product timeline.