What's not planned? Live TV shows, sports - where people are moving about randomly.
Be it on a sports field, be it in a live TV studio, very little is actually random.
You've also quoted two examples where a multicamera rig would be used. Any one camera only needs to be in focus at that 5 second grab. And there will be a director telling each camera what to follow etc. Again. Not. Random.
Autofocus isn't a focus assist or focus aid. In video it's actually a clockwork mouse. Set it off and christ knows where it will go.
If you are an individual run and gunner you won't be capturing everything as it happens immediately. You go in with a plan. You set things up where you can (i.e. the most part, particularly interviews).
Also ENG and HDV cameras typically have 1/3 to 2/3rds sensors. Far smaller than even a cropped sensor DSLR / s35 like the C100.
So these cameras are immediately much more forgiving. Focus is much more critical on larger sensor cameras (which is why I resisted a 5D2 or 3), it;s much more critical with wider apertures, it's much more critical with longer focal lengths, it's much more critical with closer subjects.
So if you run and gun, you probably want a self contained unit with a large zoom range and small sensors.
If you do use a DSLR you probably want a wide or ultra wide. You probably want to stop down a bit. And you probably want a good 2 or 3 paces betweeen you and an interview subject.
Bang: Lots of depth of field. Stills guys call this hyperfocal. Lots of movement latitude. And an on the ball operator who knows which way and by how much to correct.
I'm over egging it. It's not that difficult or I couldn't make a living at it. Seriously.
Throw AF in. No thanks. With large sensor. Absolutely no thanks.