We can't fix what happened. The June fiasco brought attention to the Fediverse and it provided a boost. A boost the fediverse wasn't fully equipped for, but a boost nonetheless.
The best thing to do is prepare for the next fiasco. And given "Reddit pays you for updoots" is still incoming, there will be a next fiasco. Make sure bugs are fixed, be able to point to some apps or alternative views that people made, and overall be a smoother transition than what was before.