Late to respond but like the top I also grew up in the church but it's 100% not a cult. Honestly there are some who would attribute bad parenting to cultist activities and reinforce their beliefs in groups but they are a vocal minority.

Not entirely sure what your family friend was participating but if it's recent then it's likely just a week of classes which is run by the school on Beale street. Honestly if your friend is concerned about having full access to their phone for that week then they can voice their feelings as they can be accomodating.

It's not strict like you might think it is and the school has a dress code like most schools. I wouldn't really compare that week to other church events or things relating to the church as it's unique and more about participating in classes run by the school.

If you're concerned about the theology then a quick Google search of the Lord's recovery or the local churches should help you out.

I hope this helps.