Caller ID on an IPhone 12 Pro Max

My wife got a call the other night from an old co-worker that we prefer to avoid. It showed up on her screen with his name and city. She changed her number long ago and had him blocked. I was upset thinking she had been talking to this guy again but she swears that he must have gotten her number elsewhere. So in my experience, if someone not on any of my contact lists calls me it will just show up as a number. Only when I’ve put someone into my contacts does it display the name when they call. Am I correct in this? Is it possible for someone to call my phone and have the full name show up when they aren’t on my contacts?