I am not very sure this is tat bad. If code breaks because dict is no longer ordered, people should have used an ordered one from the start. It's a happy accident it is faster and ordered and not bad because whoever relies on dicts bein unordered (when sometimes they aren't) deserves whatever breakage they get.
This is very similar issue that made migration to Python 3 so painful.
A lot of the code had broken unicode from the start. The difference was that it worked in python 2 most of the time and failed on special cases, while python 3 was stricter and mixing bytes with string always caused it to crash.
Once dict() is ordered and people will use that property (even unknowingly) if the behavior changes again in the future, a lot of their code will be broken.
It may be similar in that it allows for relying on consistent behavior when one shouldn't, but fixing it seems a lot easier than decades of not thinking about Unicode.
