because looking at https://www.pulumi.com/docs/reference/pkg/python/pulumi_aws/route53/#pulumi_aws.route53.Zone and following to https://github.com/terraform-providers/terraform-provider-aws/blob/master/website/docs/r/route53_zone.html.markdown#private-zone it's not expecting a list of VPC objects, it's expecting a list of VPC configuration blocks (dicts)