i personally disagree with this
although 'talent' may play a factor in getting a high atar, i personally believe that a high ATAR comes from how you study, how hard you study, whether or not you have learnt your basics properly, learning from mistakes and learning study techniques from previous top students
i dont know how you interpret 'talent' but to me the way i interpret 'talent' is that people can pick up on things easily, especially the difficult concepts
a 'not so talented person' should be able to compensate for that via various ways (such as relearning the content, learning ahead of peers by a bit, using diagrams, watching youtube channels such as KhanAcademy) hence they can get a 99+ atar (imo) as long as they do that, put in the effort and study smart
personally no
you can get 99.95 with any subject (probably not english standard or any super low scaling subject like senior science) as long as you show interest in learning the subject, study smart, hard and get all the advice from past hsc students