I'm curious how you think you were linked. Also, how you have identified that you were successfully linked?
Perhaps you still have the same social media accounts somewhere? Perhaps you used your same PC you'd formerly used when creating new ones? Perhaps your friends merely updated their phone's contact information for you rather than deleting the contact and adding new ones?
I wasn’t able to identify where it came from, but I do suspect it’s the latter — which is really hard to deal with because it’s other people leaking info about you. But the same could have happened with facial recognition at an ATM or checkout.
Personally, I’ve accepted that being an American in 2021 just means being under constant surveillance. The fantasies of going off-grid will run into the realities of your human relationships.
You mention contact linking being a possible cause of advertisers figuring out your new address, but it also wouldn't surprise me if at some point during the legal process credit industries just got notified about it. Although if that was the case you'd think that advertisers would have had the courtesy to use your correct name when sending junk mail, so... shrug.
It's a weird system that is so ridiculously good at tracking people, but still messes up so many basic details.
Name changes seem to not have been frowned upon generally if they had significance. Often they were recorded as part of a rise of status whether formally like say becoming pope or a Norse deed name style like being known as Shieldbreaker because you struck the blow that split a foe's shield in two.
As for tracking - many buggy but functional systems linger at good enough for generations with a weirdly stable whole. Even if you can get a "NULL" vanity plate you shouldn't unless you like taking the chance of receiving every ticket for cars without plates and having to dig your way out of that mess.
That may or may not be the case. It's enough to have a friend of yours who (unknowingly) posts a picture on FB with "Me with X. He/She changed his/her name and move to ...". The chances are you'll never discover where the "leak" comes from.