I think it probably was just a scam. You did right thing in changing your password. I am not sure about the need to deactivate your accounts. Here is some information that may help you now or in the future. See especially the security information.
Here is What to do after you change your Apple ID or password https://support.apple.com/en-us/HT204071
Learn about Phishing, Scams, Apple Practices,etc.
See If you see apple.com/bill, itunes.com/bill, or an unfamiliar charge on your statement https://support.apple.com/en-us/HT201382
See Identify legitimate emails from the App Store or iTunes Store https://support.apple.com/en-us/HT201679
See How to avoid scams when using Apple Pay to send and receive money https://support.apple.com/en-us/HT208226
For scam related information from Apple including reporting scams to Apple see Avoid phishing emails, fake 'virus' alerts, phony support calls, and other scams https://support.apple.com/en-us/HT204759
Identify scams related to purported apple notificationsper Eric Root.
“Apple will always address you by your name or the name they have on file for you, not Dear Customer, Dear Client or by using your e-mail address. The e-mail will be from @apple.com or @iTunes.com. E-mail addresses can be spoofed. You can go to Mail/View/Message/Show all Headers to see more. Apple emails won't have poor grammar/misspellings. Apple e-mails will never contain an attachment. Apple will never request personal information by email such as Social Security numbers, your Mother’s maiden name or full credit card numbers. …
“The only exception to the above I have noticed is if you order something from the Apple Store (apple.com), your receipt will be addressed to Dear Apple Customer. That is a receipt for a purchase you initiated.”
Learn about/Increase security
See If you think your Apple ID has been compromised https://support.apple.com/en-us/HT204145
Increase the Security of your Apple ID https://support.apple.com/en-us/HT201303
iCloud security overview https://support.apple.com/en-us/HT202303
Ways to keep your information safe on Mac https://support.apple.com/en-gb/guide/mac-help/mh11402/mac
