It's some time since YouTube began supporting automatic translation for subtitles into variety of languages. It works for every video that has automatically generated subtitles AFAIK.

Currently NewPipe only supports automatically generated subtitles in English and of course manually embedded subtitles, but nothing more AFAIK and so I presume it's extraction is not supported by the NewPipe Extractor.
I think it would be cool and could help a lot of users if all these subtitles would be extracted by NewPipe Extractor and would be made available in NewPipe.

The only issue I am thinking about is if these automatically translated subtitles are hosted in the same format on YouTube servers as the original ones or if they are translated in real-time. If that's the case it would make implementation probably much harder.

Here's an example of YouTube video that has automatically translated subtitles. (You will first need to enable English subtitles for the automatic translation option to show up.)