> has to contend with that reputational damage if they don't take steps to prevent this sort of thing before it happens (like letting the developers know that private-on-paper API is going to be yanked in advance, or making it mechanically impossible for anyone outside of Apple's own code to invoke that API long before someone depends on it).
Again, that is what dev builds are for. Developers had months to verify their software still works on an OS that has confirmed release date and has very high ration of users that install the latest and greatest.