I don't mind either. And I have a commercial Mac application written 98% in Swift to maintain.
Now the risks were known when we green fielded the project. It was certain that Swift syntax and the frameworks would change in the future. But the time we saved in development makes up many times for the maintenance burden now.
Luckily refactoring strongly static typed code is not that of a fiasco :)
Yes, not really a problem in that case. But let's not forget that this release also contains nearly 50 other source breaking swift-evolution proposals (full changelog here: https://github.com/apple/swift/blob/master/CHANGELOG.md).
But one of the things I like about how the language is begin developed is that everyone involved is aware that having the language in a constant state of flux is painful, and try to provide useful warning messages (or wizards if you use XCode) for those that will need to update their code to a newer release sooner or later.
Python 3 did implement pretty significant library changes, though mostly organisational (namespace restructuring, merging of C accelerator modules, renamings, removal of deprecated modules, …): https://www.python.org/dev/peps/pep-3108/
Now the risks were known when we green fielded the project. It was certain that Swift syntax and the frameworks would change in the future. But the time we saved in development makes up many times for the maintenance burden now.
Luckily refactoring strongly static typed code is not that of a fiasco :)