This year was the tipping point for the US market, they weren't readily available until late summer. I'll have a (ground) wireless lawn robot next year one way or another, it would bring me more satisfaction to build one but that doesn't mean I'll actually do it.
That's new — but those are still $5000 models "designed for professional fleet use", a little on the steep side. I'd give it a little longer for that to percolate downmarket towards the likes of the Navimow which is around the €1500 level.