Like all of you, this issue is annoying for me. I also observed that the file extension also shows on all other computers connected on the same iCloud account.
Before I would debate about if the feature of hiding the file extension has been removed or not, I would first first consider these facts:
· with files that we don't modify, it is still possible any time to mask or unmask the file extension
· with files stored on local folders (not on iCloud folders), even modified files still keep their file extension masked
Suggesting that we did not loose any feature, or this "option" has not been removed.
I have also observed these:
· in my case, Pages, Numbers and Keynote do not force me to save with the file extension visible (I guess this is
something I have set up initially), other users should be able to do the same
· the issue also happens with most file types (ie, .png, .pdf, .docx, .xlsx, .rtf, and more), and not only the
iWork series (.pages, .numbers, .key)
· when moving a file from a local folder to an iCloud folder, the file extension appears temporarily, then disappears;
it is like the synchronization process needs to unmask before doing its job; the same happens when renaming
· after saving a file to a iCloud folder, the file is then synchronized to iCloud, like for moving or renaming, the file
extension appears during that time, but it does not re-mask when done
That let me believe that something may not be happening as it should during the synchronization process, and this is why we have this issue.