They do more than just the phone number and name. https://www.howtogeek.com/768652/what-are-facebook-shadow-profiles-and-should-you-be-worried/
It talks about the use of photos, people mentioning you in a post, etc. Sure, facetook publicly said they would be backing off of visual recognition, but how much do you really trust that company to do jack-diddly if there is potential profit? Anyway. If you change your phone number, but the same group of people still have you in a 'field of contacts,' their tools can almost certainly fit those puzzle pieces together. Same if you change the phone number. Identifying people is easy if you have metadata.
I think that one is finally starting to die off, aside from the last gasps of a man in prison. It takes a while for real science to filter through to common knowledge, and I'm constantly seeing the corrections about wolves and alpha status as flawed thinking.