By definition, however, a Hohmann transfer is a minimum energy transfer. Any variation in timeframe, either longer or shorter, is no longer the minimum energy. But I have a history for nitpicking scientific inaccuracies. Especially in movies. You don’t want to hear them.
Rereading the article and a bit more reading on the subject, the author implies going to Mars in less than 9 months(Hohmann transfer)as some new concept. The Perseverance Rover spacecraft makes 5 trajectory-correction maneuvers along the way to arrive in ~6.5 months. The Mars transfer type depends upon what needs to be done when the spacecraft arrives at Mars.