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.