Can a previously trusted but dropped phone number be linked to my identity graph in Apple Music?

• Trusted numbers in Apple ID: When you add a phone number as a trusted number, it’s used for two-factor authentication and account recovery. If you remove it, Apple no longer uses it for those purposes. It doesn’t remain active in your account’s security settings.

• Apple Music and phone numbers: Apple Music subscriptions are tied to your Apple ID, not to a phone number. Even if you once used a number for verification, the subscription itself is linked to your Apple ID credentials (email + password + active trusted numbers).

• Identity graph concerns: Apple does maintain records of account activity for fraud prevention and security, but there’s no evidence that they secretly reattach old, dropped numbers to your account “on the back end” without your knowledge. Once a number is removed, it’s not considered trusted anymore. If you later change devices or numbers, Apple only uses the current trusted numbers you’ve explicitly set.

• Transparency: Apple generally informs you when a trusted number is added or removed. You’ll get notifications and can always check your Apple ID settings to see which numbers are currently linked.

A year later, Apple would not silently reattach your old number to your identity graph just because it was once trusted. If it’s removed, it’s gone from your trusted list. Your Apple Music subscription remains tied to your Apple ID, not to that old number.

If you feel an unauthorized person/app is remotely using, controlling or monitoring your device, then that is possible only if you have done one or more of the following Don'ts...

1. Don't hand over an iPhone to kids or to a stranger without Enabling Guided Access
2. Don't share Apple IDs
3. Don't Jailbreak
4. Don't share sensitive information pertaining to your device
5. Don't give in to Phishing
6. Don't plug in your device in Airports and Public places through third-party cables and trust the device. Beware of Juice Jacking. (Especially in India)
7. Don't leave your iPhone unlocked and unattended in public places like offices, schools, malls, etc.

If one of the above is true then quickly change the Apple ID Password and Return iPhone settings to their defaults.

1. Immediately change your Apple ID password
   1. Go to Settings → [your name] → Sign-In & Security → Change Password.
   2. This signs out anyone using your account.
2. Enable Two-Factor Authentication (if not already): Same menu → Two-Factor Authentication → Turn On.
3. Check for any unknown devices linked to your account:
   1. Settings → [your name] → Devices.:
   2. If you see anything you don’t recognize, tap it → Remove from Account.
4. Check for unknown profiles or device management:
   1. Settings → General → VPN & Device Management.
   2. If you see a profile you didn’t install, tap it → Remove Profile.
5. Check Accessibility & Screen Sharing settings
   1. Settings → Accessibility → Switch Control, Voice Control, or Remote Control — turn off anything you didn’t set up.
   2. Settings → General → AirPlay & Handoff → make sure AirPlay is set to Ask or Never Automatically.
6. Sign out of iCloud everywhere and reset
   1. Go to Settings → [your name] → Sign Out (you’ll need your password).
   2. Then back up your photos to iCloud or your computer.
   3. Go to Settings → General → Transfer or Reset iPhone → Erase All Content and Settings.:
   4. Set it up as a New iPhone (not from a backup), so nothing suspicious is restored.
7. Update iOS: Always keep the latest iOS version for security fixes.

If a person has ever had your passcode, they could’ve installed something quietly — so the full erase and setting up as new is the safest option. How to factory reset your iPhone, iPad, or iPod touch

You may get better and prompt responses if you may kindly provide the iPhone Model that you have and the iOS version if it is known to you and re-post.

With the limited information that you have provided, It is hard to even guess the problems faced by you. 

You may get faster and better responses to your query by --> Writing an effective Apple Support Commun… - Apple ...

Please re-post with detail so that someone else can help.