Does Whatsapp notifies if my security code has changed to people I don't have in my list of contacts? I know Whatsapp gives you a notification when someone change their security code (eg: when they change their smartphone) I am wondering if this is also the case when that person doesn't have you in their list of contacts.

To make it clear, for example, if I am in a group and I have only some of the members added to my contact list, and then I changed my phone, will they all be notified or only those I have added?
If you're in a group and your security code is changed then every member of that group would be able to see that notification. I'd observed this many times even though neither me nor them knew each other or had each other's number saved. They would see your number in the notification (not technically a notification), not the name.