I am a huge fan of real estate investing (rentals) but in the BYU case there are a few caveats, good luck.

1) are your kids going to want to live there all years and what are odds they stay there every year (mission/marriage)? Is there a cooler place that their friends want to live at but your kids can't because they have to live in the unit you bought? Your child looses flexibility.
2) while BYU student housing is near recession proof from a vacancy standpoint, it has its costs - from an investment perspective, the key to successful rentals are long term tenants. With BYU they are not long term and all the turnover costs money
3) it can be 2-8 times the work of a typical rental, not to mention the wear and tear as you have a separate contract for each student vs one single household. Rather than one lease agreement, you have a contact with each student
4) if one of the roommates struggled with bills it becomes awkward as you or your child has a relationship with them
5) The returns aren't great (much better markets) and you also have to provide furnishing - just one more headache. But your case may be less about the return and getting something back rather than paying someone else

I think ultimately you should ask two questions: 1) how will this be for my kids? 2) will this complicate my life in any way, and if so, is the savings/return worth it?

Good luck