Journalists who deal in sensitive material should not trust any of that to any third parties to the greatest extent possible. If I were Chinese intel or the FBI, otter would be one of the richest targets imaginable for some of the most prized information on earth, i.e. high-value intel targets spilling secrets in "full-confidence" and divulging information they might never reveal even in court. otter also transcribes medical/psych convos and legal discussions as well, bringing the sum total of what they could "know" about any human, willing or not, to scary levels.
Journalists who are casual or reckless with this kind of data shouldn't be in the business, and companies that don't make these kinds of risks apparent to their user base, or go to lengths to disguise a clear conflict of interest as bad support should not be in that business either.