In the context of a cost-cutting exercise, it's pretty obvious that the middle of the hierarchy is where you're going to do the cutting.
You're not going to cut at the top, because there aren't enough individuals there for that to add up to a total amount of money that's actually significant in the grander scheme of things, and the political repercussions
for you as a leader would be far worse.
If you cut at the bottom, you cut the part of the workforce that's actually comparatively cheap on a per-head basis, and you basically give a demotion to everyone who is left who used to be a manager, because you're either cutting their team size or demoting them from manager to IC. So, the workforce you'd end up with would be more costly and less motivated than what you end up with if you cut the middle of the hierarchy instead.
So, this is basically just a corporation exercising the only option it really has in this situation, and dressing it up as some kind of deep insight about organizational structure.
But, even if the context was different, even in the context of a growing and successful business, "flat structure" and "self-organizing" are often euphemisms for other things.
For example, it could be a euphemism for a kind of social Darwinism where, instead of appointing a manager and risking the appointment of a "weak" individual, you just wait to see who it is who ends up beating the others into submission, thus, by definition, ending up with the "strong" ones bubbling to the top of the hierarchy. It's needless to say that this process is cruel and creates a ton of collateral damage.
What I've also seen in connection with "flat structure", "self-organization", and "bottom-up" rhetoric is the situation where the company is actually run by a secret cabal of people who know damned well who's on the inside and has power, and who is on the outside and does not. But the people on the outside don't know that, and are instead given the "flat structure" and "self-organization" rhetoric. This reinforces the secrecy of the power structure, and serves as a convenient gaslighting device to make it look to the outsiders like their powerlessness is their own fault, rather than the organization putting them in a place where they have no power.