For a person to get placed on a team at Amazon, the manager must be making some representation that they need another employee. Amazon isn’t going to waste headcount by giving it to managers who don’t ask for it. This means managers have control over whether hires are joining their team. Therefore a manager can execute the plan of hiring to fire. It doesn’t matter whether they have the power to approve a specific candidate.
Obviously if you are forced to cull X% you are going to try to maintain 1+X% staffing level.
Whether or not this actually happens, I don’t know. Do I think that managers (or really anyone else) can use soft skills to exert some influence some of the time? Having participated in many such panels, I think it’s pretty doable despite what many people claim because of the discussion process that happens.
The need to get vacancies filled.
Where is this data?
>Instead, Amazon managers are hiring people they otherwise wouldn't, or shouldn't, just so they can later fire them to hit their goal.
And as OP is correctly pointing out, that can't happen, because the bar raiser can veto any hire they think is unqualified. Or at least it can't happen without the bar raiser colluding - and since the bar raiser is not the hiring manager (or even from the same part of the organization as the hiring manager) and they are not being evaluated on the UAR, they have no incentive for this.
If, as you suggest, managers were hiring _qualified_ people with the intent of firing them... I guess there's no way to prove that isn't happening but FWIW, I'm also at Amazon and have been part of a bunch of interviews and I've seen no evidence of that.