I want to see original movies in AppleTV

Any available soundtracks are the responsibility of the rights owner or studio that offers the movie in the Apple TV app in your country. Apple has no control cover this.

In general available additional languages can be found by selecting the text balloon above the time line indicator while watching a movie.

click here ➜ Change subtitles or languages for videos in the Apple TV app - Apple Support

Antmen wrote:

Thank you very much for your response—I truly appreciate it. I believe I may not have expressed my point clearly.

I am not looking for an additional subtitle or audio track. Rather, I would simply like to watch movies in their original versions, with the original voices as recorded on set, as presented in cinemas, and as intended by the filmmakers.

That would be an audio track. If it defaults to Italian language being spoken, then opening the audio icon may let you select the original audio language that was filmed and used on set. That's what Audio tracks do. They change the audio and spoken languages for the selected movie to other available languages.

This does not seem to involve any copyright issues, nor would it require any extra expense for the rights-holding studio. Given that the original version of a film already exists, I am curious as to why it is not made available by default.

Again, Studios upload the film with whatever audio track or tracks they decide. If it defaults to Italian and no other audio track option exists, then they chose not to upload it for whatever reason. It may not have to do with expense.

Could you help clarify why the original versions of most of the movies are not accessible on Apple TV in Italy?

I can't. Again, as I said, the studios make this choice. They upload the version they choose to with whatever spoken languages they choose to. If the original language is not available, it's because they chose not to upload that audio track for it.