It would still be relevant, it just wouldn't be as obvious.

On some airlines, First Class is referred to as Employee Class, because the gate agents are so diligent at upgrading all employees before upgrading any elites. That really leaves a bad taste in the mouths of elites passengers - who should get that upgrade. AA is not that bad, but it still does happen, we all see it, and it should not happen. If crewmembers traveled out of uniform, it would not be so blatant, and therefore not so disagreeable, but still would be wrong.

If AA took $20 out of every FA paycheck (with a deduction on the paystub saying "Give us money - we need it more than you do" that would be wrong, it would be obvious, and would cause a lot of discontent (and rightly so) among FAs. If AA took the $20 by adjusting the amount of one of the other deductions (for example, Social Security), but routed the $20 to their own pocket, it would not be so obvious, and therefore not cause as much discontent, but it would still be just as wrong, perhaps more so.