It isn't 1: They're not publishing their ML researchers' daily activities and experiences.
It isn't 2: This isn't what would be generally understood as a 'periodical' or 'magazine'. It doesn't even resemble the trade publications that are often published by larger businesses.
It certainly isn't 4 - Apple isn't giving away terribly detailed accounts of their research activities.
The meanings of words isn't set in stone, rather they change over time. As long as people generally interpret the message close to how it was intended to be interpreted, it's fine.
It isn't 2: This isn't what would be generally understood as a 'periodical' or 'magazine'. It doesn't even resemble the trade publications that are often published by larger businesses.
It certainly isn't 4 - Apple isn't giving away terribly detailed accounts of their research activities.