I think there’s a much simpler explanation. Someone was tasked with writing a computer program to generate workouts at a range of levels and a particular duration. No sanity check was then applied to the resulting long cool-downs for workouts. I did one of these yesterday. It’s a 60m workout trapped in a 75m body.
I’ve seen time at intensity defined as interval + rest. So for say 6x2m/4r you should count 36 minutes of intensity.