Adobe XMP future

XMP is part of Adobe products since CS2 so when the question to when that will be implemented seems answered:

https://en.wikipedia.org/wiki/Extensible_Metadata_Platform#:~:text=Public%20Patent%20License.-,History,the%20International%20Press%20Telecommunications%20Council.

But are talking about accessing XMP with UXP scripting? Then it relies on every product team to implement and that only Adobe can tell. But for InDesign, you can already pick xmp metadata with UXP:

//HelloWorld.idjs
//An InDesign UXPScript
//
//Creates a new document, adds a text frame,
//resizes the text frame and adds text.
var myDocument = app.documents.add();
var myTextFrame = myDocument.pages.item(0).textFrames.add();
/*Set the geometric bounds (the location of the top, left, bottom, and right edges) of the text frame. In this step, the script uses measurement overrides ("p" for picas) to ensure the text frame is the correct size, regardless of your default measurement units. The locations are provided as a list, or array, of values; each scripting language has a slightly different way of creating an array. */
 myTextFrame.geometricBounds = ["6p", "6p", "24p", "24p"];
//Add text to the text frame by setting the proporty of the content to a string 

var creator = myDocument.metadataPreferences.creator;
myTextFrame.contents = "This doc was created with "+ creator;