The content of org.jboss.eap.channels:eap-8.0 manifest starts like:

schemaVersion: "1.0.0"
name: "Manifest for EAP 8.0"
id: "org.jboss.eap.channels:eap-8.0"
description: "This manifest provides the latest upgrades to provision EAP 8.0"
vendor: 
    name: "Red Hat"
    support: "tech-preview"

The support: "tech-preview" is most likely wrong and should be changed to support: "supported" since using the manifest is the supported way how to update EAP 8 instance.