Nobody has to sleep during an extended rest.
Really.
The requirement is that you engage in no strenuous activity. Characters normally sleep during this time, but they don't have to.
However, if, at the end of an extended rest, a regular character hasn't slept for at least 6 of the past 24 hours (note, those 6 hours don't have to overlap with the period of the extended rest at all), they do not gain the benefits of the extended rest.
What the mul is getting is an exemption to that last part. Instead of having to have slept 6 hours in the past 24, they simply have to have done it in the past 72.
They still need to spend 6 hours not engaging in strenuous activity to do an extended rest.
Really.
The requirement is that you engage in no strenuous activity. Characters normally sleep during this time, but they don't have to.
However, if, at the end of an extended rest, a regular character hasn't slept for at least 6 of the past 24 hours (note, those 6 hours don't have to overlap with the period of the extended rest at all), they do not gain the benefits of the extended rest.
What the mul is getting is an exemption to that last part. Instead of having to have slept 6 hours in the past 24, they simply have to have done it in the past 72.
They still need to spend 6 hours not engaging in strenuous activity to do an extended rest.
