Regardless of what the GoPro and Ambarella marriage can provide in tandem hardware it is clear the company wants to branch out of the fledgling sales of GoPro which have tanked in recent quarters and the stock price from a high near a $100 USD is now trading at a mere $12 which is half the IPO price. By branching out it seems they want their chips in many more imaging devices and be less affected by the GoPro product cycle.
The announced H2 and H12 chips are able to provide beefy 4k specs at high frame rates for mobile devices at a mere 2 Watts of power. As to 1080p frame rates it will remain to be seen how this powerful new chip can handle that in a camera design and how it is implemented to squeeze that performance. 120fps at 4k from the H2 in theory should be able to yield 480fps at 1080p just counting the Pixel processing. This however can be limited by the rest of the components like imaging sensor.