"In their current form, the YAML pipeline templates hardcode "master" as the default triggering branch. Now that customers can specify their default branch, we should be able to leave that as a symbol in the template and have the setup wizard replace it with the actual (or chosen) default branch name."
https://dev.azure.com/mseng/AzureDevOps/_workitems/edit/1765369
"In their current form, the YAML pipeline templates hardcode "master" as the default triggering branch. Now that customers can specify their default branch, we should be able to leave that as a symbol in the template and have the setup wizard replace it with the actual (or chosen) default branch name." https://dev.azure.com/mseng/AzureDevOps/_workitems/edit/1765369