My flat startup just became a pyramid. Now what?

I work at a startup that was, until recently, embarrassingly flat. No middle managers. But not because we were believers in consensus - we just had initiatives from the CEO and CTO, and a lot of people scrambling to achieve them.

To my eternal surprise, we're doing better than most of our competitors, we've grown 10x since I joined, and no layoffs are on the horizon.

I really thought I'd be leading a project by now or managing, and I essentially am! Just not officially.

So we're finally getting some structure. But not promoted from within. All hired from outside the company. We've gone from having no VP of anything to having Executive VPs who hire other VPs who hire Directors, in the space of a few weeks.

I really thought we were going to hear that our CEO had been fired by the board, but to my surprise he has not been.

I'm not sure what to think about it.

I'm looking for guidance from people who've experienced something similar. I've been through chaotic re-orgs, but those were at failing companies, with accompanying layoffs. This company is doing okay but it's suddenly transformed and I don't know if it's good or bad, or if my career prospects just became better or worse.