It's not withering away because of minor mistakes; it's withering away because of
major mistakes. Those mistakes are largely in corporate governance -- this is the reason so many are furious about the $2.5MM salary for a CEO at the helm of a market-share death spiral. Every single product line except Firefox is an also-ran from a revenue standpoint. How does Baker respond? Fire the Servo team, and tell an interviewer there will be a focus on (among other niche services) a "VR chat hub." Oh, and any salary reduction for executives is 'a burden.' (
https://twitter.com/lizardlucas42/status/1293232090985705478)
All this from an organization with the audacity to solicit donations from end-users.
So no, I would not say Mozilla has learned anything or worked to prevent it happening again. What has changed since the January layoffs except for the scale of the layoffs? In no world is running a company such that you have to boot a quarter of your workforce 'minor mistakes.'
The silver lining is that Mozilla's race to receivership won't make much of a difference. They haven't done much for web standards beyond co-signing Google's railroading of the standards bodies, and they couldn't even stand up for video or DRM standards either. Every download of Firefox ships Google Analytics, installer stubs for Cisco and Google video blobs, and a configuration that shunts your DNS lookups to yet a third private corporation. With friends like Mozilla, who needs enemies?
In short, the organization is utterly rudderless (and has been for nearly a decade), incapable of supporting itself without search engine subsidies, and not achieving any of the ideological goals it espouses. What we're witnessing now is what happens when you can no longer coast on branding. What's down this road, after some deck-chair rearranging, will be cessation of operation of the for-profit arm and a new direction for the non-profit arm, which might survive that. Time will tell.