Talos on IncusOS is likely a very interesting stack that I intend to play with hopefully in the near future.
First time I heard someone call it blue-green OS updates instead of A/B OS updates.
Same concept, I guess. I'm a platform engineer / SRE, and blue/green is a more common way of describing that way of deploying applications so I didn't even consider it could have a different name on the OS layer.