OpenAI to double workforce as business push intensifies

Maybe they know something more than they advertise publicly

Hiring sprees signal growth to the market. Growth is the dominant metric for pumping the IPO stock price considering they're nowhere near profitability.

Doesn't matter if they're needed or not. They can always be fired later.

If your work is parallizable, you can get more done. Eg more enterprise features you weren't currently going to do, more sales calls, more marketing campaigns, etc. mythical man month only applies to highly coupled work with large ramp time. Engineers often don't spend enough time planning to keep work decoupled (and with less people it's unnecessary overhead to do so).