[IBM]

They also told him that, from their perspective, the two accounts belong to the same entity because they have the same payment details and test devices.

There was no reason for them to know that this developer purchased an account for someone else and gave them his test devices (which sounds like an excuse anyone accused of anything gives when they're caught).

[Mithaldu]

Apple would also be aware that various sets of contact data are attached to those accounts, but ignored them. The linking is furthermore also only done on their side via metadata, and not communicated to, or done by, the developer.

[eridius]

Of course the linking isn't communicated to the developer. It wouldn't be an effective anti-fraud mechanism if it was.

[Mithaldu]

I'm not saying they should. I was just enumerating some ways in which notice could've reached him, but didn't, in response to the GP post trying to claim he was notified.