"just have it widescreen in the first place though"
True,also it might have started as just a cute, his grandfather throws a sock at him and the switch in viewpoint occurred later and they didn't correct for continuity amongst, as you say, the multiple takes.
He edited in portrait, and also in landscape (in the morning on the couch): possibly that gives better access to toolsets or has some other advantage? The one shot in portrait shown from behind the subject was when his grandfather throws a sock at him, an easy crop.
Probably not, but President John Adams might have been when he set up the first American Public Health Service built and maintained by mandatory fees paid by citizens, in 1798.....Oh my a "Founder" was a commie!Or.Not.
There's an opt-in auto-uptdate question during the installation. The admin for the machine seems to have selected "Yes". That's editable under "System Preferences...App Store... Automatically check for updates, etc."