Italian outlet Aggiornamenti Lumia claims that Apple will be releasing an as-yet-unspecified new app for the Windows 10 platform. This rumor seems to be in consonance with speculation last year that Apple was working on a "next-gen" media app for Windows. If the app is built from the ground up for UWP, it might actually make its way over to Xbox, as opposed to the current Microsoft Store version of iTunes.
https://www.notebookcheck.net/iTunes-on-the-Xbox-Series-X-Report-indicates-that-Apple-plans-to-release-new-Windows-10-app-and-it-might-just-run-on-Microsoft-s-new-console.481289.0.html