The only time this cloud-based transcription is used is during a Zoom meeting, which is already in the cloud.
When you join a new Zoom Meeting we prompt you to ask if you want to record & transcribe the audio. You can choose to do this selectively for each meeting, or not record & transcribe any of them if you aren't comfortable with cloud-based transcription.
That said, we do plan to move away from cloud-based transcription, likely with Whisper from OpenAI.