Netflix has been "testing the waters" at GCP for years. And as their infrastructure grows, relying on a single cloud provider would be a silly limitation to put on themselves. Disaster-recovery/failover is a very natural use case for multi-cloud deployments. Not to mention that for certain workloads and patterns, GCP is cheaper and better. Netflix operates at a scale well beyond what most AWS managed services can really address, and broad cloud patterns like object storage, function-as-a-service, VMs, and networks, can be abstracted away given enough resources, which Netflix surely has. Not to mention that at Netflix's scale they have real leverage over cloud providers and what services they offer. They would be stupid _not_ to be playing AWS and GCP against each other for pricing (on which they already get a huge discount) and features.
I'm guessing there's some project getting underway to move/duplicate some subset of resources hosted in AWS on GCP. It's likely a huge project that dwarfs most corporations entire cloud presence, but I'm guessing for Netflix it's a small piece of a giant puzzle, and that the vast majority of their operations are still centered at AWS and will be for years and years to come.