Hey Aaron, both the links are broken now. We logged a case around this topic back in late 2020. And the bug number and description was as follows:
BUG-000135141 : ArcGIS Portal Hosted Services do not honor Feature Templates default values in ArcGIS Pro 2.6.2
It says it was resolve in 2.9 but I still get weird behavior in Pro 2.9.4 to Portal 10.9.1. Our solution was to hard code the templates in the layer file or do as @tkeith1106 mentioned as well.
And the issue as described in our case:
In ArcGIS Pro 2.6.1 & 2.6.2, the GUI for the Manage Templates Pane shows that the feature templates exist... both auto generated and when manually deleted and recreated. We can check the properties of the individual templates for any layer in the map and everything looks normal (all the default values are correct). If we then publish that layer as a hosted service to Enterprise 10.7.1, the feature templates are not honored beyond the field that controls symbology (unique renderer). While investigating the cause we saved the layer to a *.lyrx and the map to a *.mapx files. A look at the JSON for both yields an issue and makes it obvious why the hosted service doesn't honor the feature templates... looks like there is nothing to honor from the Map CIM Object. Notice in 2.6 that the toolProjID is all zeros and the default values only include the field controlling symbology.
The project, map and layer was authored in 2.6.x. We then opened the project in 2.5.x, saved it and then saved the layer as .lyrx and the map as .mapx to inspect the JSON were everything appears normal. The results from both are below.
- Justin Reynolds, PE