security breach

iOS / iPadOS devices cannot be hacked or infected with Virus / Malware / Spyware if it is updated to the latest iOS/iPadOS unless you have intentionally downloaded spurious software or unauthorized apps directly from the internet and installed on your device or/and have Jail Broken. 

It (Hacking) also depends on how careful are you in sharing sensitive and valuable information pertaining to your iPhone such as Passcode, Password etc with your friends and family members.

Be careful when sharing the device's sensitive and valuable information with friends and family members.

Thumb Rules:

1. Enable  Guided Access before handing over an iPhone to kids
2. Don't share Apple IDs
3. Don't Jail Break
4. Don't share sensitive information pertaining to your device and payment methods
5. Beware of Phishing
6. Use a strong password for all the Apple IDs created and used by you --> If you think your Apple ID has been compromised - Apple ...

no it has nothing to do with your iPhone being hacked.. (your iPhone wasn't hacked)

those warnings are meant to inform you that you are using repeated passwords, weak passwords, passwords that have been found in breaches.

It's totally up to you what you do with that information. It doesn't necessarily mean the associated account is compromised, but it is likely at higher risk of becoming compromised.