What "begins"? There's been several Unity AI companies come and gone already, including some mergers and acquisitions. [1] comes to mind.
Epic jumped on the AI bandwagon a while ago.
Unity has been the laggard in terms of AI adoption. If anything this is an "ending" to their old ways.
True that there has been many companies with their own implementations but I feel like a native implementation done by unity will have a huge effect. There is just so many indie devs using it, when the unity team starts adopting it more like how they have started with this cli, I think the use of AI in game development will skyrocket