Aurora Serverless V2 Postgres Cross Region Replica

Aurora PostgreSQL DB clusters don't support Aurora Replicas in different AWS Regions, so you can't use Aurora Replicas for cross-Region replication.

Taken from: https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraPostgreSQL.Replication.html

However, you can add readers in the same region with Aurora Serverless v2 Postgres.

Finally, you would be able to create cross-region read replicas with Aurora Serverless v2 in MySQL 8 and MySQL 5.7.