Set Home Flexipage as Org Default via the API

Question

I have a new Lightning Home Page that I would like to push out to my customers and set it automatically as the Org Default via the metadata API. Salesforce documentation here makes it sound like its a possibility by setting the sObjectType as null but its not working. So I am wondering now if its even possible to set the home page as a default programmatically. Any thoughts?

{
actionName: "View",
comment:
  "Action override updated by Lightning App Builder during activation.",
content: "My_New_Home_Page_Layout",
formFactor: "Large",
skipRecordTypeSelect: "false",
type: "Flexipage",
pageOrSobjectType: "null",
},