The only option for subtitles in the original language before was Subtitles for the Deaf and Hard of Hearing (SDH/CC). These subtitles include dialogue but also audio cues such as

You can find the new dialogue-only subtitle option by heading to Netflix’s language picker while watching a supported title, choosing the English tab, and then selecting the English option. You’ll also see Netflix’s existing option, English (CC), which shows dialogue and audio cues.

Noting the increasing reliance on subtitles by its subscribers, Netflix is adding a new dialogue-only option for subtitles on its original series.