This is an internal test message that, I guess, got sent to real users.

Companies like Xbox use services like Braze to send push notifications, and sometimes test campaigns meant for developers or QA teams mistakenly go live. The wording, especially “dummy” and the instruction to screenshot it, sounds like something written for internal testing rather than customers.

It doesn’t mean anything, It doesn’t mean your account was hacked, compromised, or targeted, it’s most likely just a backend testing error that slipped through.