How would this scam work? Why would someone pose as a locksmith specifically?
The only thing that should come up is actual local locksmiths.
As far as I can tell its a national company with an overseas call center, the scam is that it looks like a local company - at least they can sell a lead gen to someone that can open my lock.
I've heard worse happening in other cases where they drill locks and then quote much higher than $200 after they do it, it's sadly common.
I've read that if you let them work on your property, they will claim your bog-standard lock is unpickable, and charge you an exorbitant amount to drill it (destroying the lock) and replace it.
Almost everyone who calls a locksmith is in a hurry, dealing with something unfamiliar, so people are susceptible to this.