On the other hand, it's already difficult to retain talent, and a single good manager can be transformational for a team. Between this and the RTO shenanigans — both of which seem to be widespread across the tech industry these days — it's tough to see why talented managers would stay, let alone put in hard work.
Overall, it feels like an incomplete solution. If we as an industry are going to move away from headcount as a professional growth metric, we need to have some other, more direct way of measuring the business impact a manager delivers so we can reward that.
Standing up and telling a roomful of high-leverage hires that their career trajectories are frozen for 2-3 years is probably not a winning strategy by itself. If I were a hungry startup founder, I'd read this as an invitation to ramp up recruiting.