I currently migrating from old CUG to new and stumbled with the following problem: in the previous version, we could add property cq:cugPrincipals to the page template, and all pages created with this template will have this CUG by default. But in the new version, we have to use rep:CugPolicy node with rep:principalNames properties for this. I create this node under the page template and create a page with this template but it does not appear in the page structure and the page doesn`t have configured CUG by default. Does it even possible with the new CUG approach? Maybe I miss something?
I think you need to create a node rep:cugPolicy (same jcr:primaryType and a property with rep:principalNames) and the parent node should have jcr:mixinTypes property, if you're using static templates.
In case you've added cug through Initial Page Properties in the editable template and it doesn't show up in the content/ page, a possible reason could be that rep:cugPolicy node is getting created directly under the 'initial' node and not under 'root' node and the page is created, it only copies the nodes under 'root' node and leave other nodes. If this is the case, you may want to check with Adobe support.