Learn English – What does the phrase “in stark terms” mean

To "get all up in something" is relatively recent slang (no more than 15 years old), and should probably not be used in any formal context. Roughly translated it means "to get extremely (possibly uncomfortably) close to something or someone".

She was getting all up in his face, shouting, "You'd better stop messing around and start treating me right!"

Without additional distinction (i.e. "get all up in that") you can probably assume some kind of crude sexual connotation.

In the source you mention the author uses it ironically, possibly in order to make the text feel more accessible to young people. In my opinion it's awkward, like someone who has never been cool who uses a certain slang (incorrectly) to try to sound more cool ... but other people might like it.