I think you took too much from implication. TFA states that they are getting promotions. Everything else is assumptions:

1. They are considered high performers (maybe promotions are on a schedule?)

2. They are actually high performers (some people can bullshit their way through a job for years).

3. They are outperforming a hypothetical person who didn't cheat on the test and would have been hired instead of them with an honest assessment.

If an org can’t tell who is good and worthy of promotion when they’re working for them every day, they have no chance of doing so in an interview