Years ago when I was using ECS on EC2 I used the ASG TERMNATING lifecycle hook to setup a "graceful" termination operation which would drain the ec2 container instance of containers before terminating it. Is this still required with ECS on EC2 in 2022? Or is there more integration between ECS and ASG now?

I think the ecs agent handles that, including for spot instances, if configured? You could try poking around https://github.com/aws/amazon-ecs-agent for confirmation