This was really boring from a security or forensics perspective. Nothing really substantial in there. But fortunately there are other angles to view this document from: if this is authentic, it says that the richest man on the entire planet...
...uses a two year old phone. I mean, I like my iPhone X too, but hey, if I had like north of 100 billion dollars, I would certainly spend about 1500 of those dollars for the newest iPhone generation every year (especially if my older generation has an unfixable bootloader bug compromising its entire security architecture).
...exchanges silly meme pictures with ostensibly funny texts with his billionaire friends.