Its not a new thing. I worked for a large British Telecoms company (who shall remain nameless), and they did these pretend hackathons fairly often.
The usual formula was this:
1. middle managers feel pressure to deliver something (anything!) as projects aren't going that well.
2. having many terrible ideas, but not being able to implement them, they decide to create a hackathon
3. their sh*te ideas are distributed to their poor dev team, who are instructed to present them as their own fresh ideas
4. everyone trudges miserably to some terrible venue, the bed, board and food is dreadful.
5. after 2 days a C-list senior, desperately failing to hide their contempt and boredom, is pressed into 'judging' the terrible ideas.
6. the 'judges' and middle managers get together and arrange some kind of fix up
7. everyone's a loser.
well, im glad i got that off my chest!