My iPhone was stolen
My iPhone was stolen, and was either turned off or put on aeroplane mode and so on Find My iPhone it still says that the erase is pending. The thief's seem to have now wiped my phone themselves and got my phone number (which I have now transferred onto my new phone). I was called twice by an unknown number who I couldn't call back as it was restricted. Then I was contacted via a number 8850 to say my iPhone had been found and click on the link to view the location. The link is clearly fake, and is asking for my apple id and password. Having read into this, Apple appears to have safeguarded their phone where even if they're wiped they can't be used as a new phone unless I remove the phone from my iCloud.
What I need to know is if i now remove my stolen phone from iCloud does that mean they can never access my personal information or hack my iCloud, but they can now use my phone as a new phone?
If so I'd now prefer to make 100% sure that they can't hack or have access to my phone or iCloud.
iPhone 11 Pro Max, iOS 14