Actually, I think it's possible that the ownership/beneficiary issues may be at the least touched on in this case, sort of in line with the follow-the-money philosophy.
The site below supports what you said. A Fideicomiso (like a U.S. estate trust) is required for "foreign individuals or firms" to purchase property in certain areas of Mexico. When JO in the press conference said that the Mexican home was a family investment, it could be that the family created a corporation made up of family members in order to purchase the property for the benefit of all family members, reducing the amount each person would contribute to the purchase of the property. It seems as though property would not have to be paid for outright, but could be paid for over time.
My guess is that this is the arrangement referred to by the reporter who said the Mexican property was owned by members of the Garland (PG?) and the Liknes families.
Therefore, it is logical that every Fideicomiso requires the naming of beneficiaries.
Much more information can be found on this site.
http://www.forevermazatlan.com/Bank_Trust/page_2138557.html
On another site I found this information, which I found very interesting in relationship to the possibility of the family forming a corporation either in Canada in order to purchase as a foreign corporation, or incorporating in Mexico as a Mexican corporation. This would also tie in the the pictures someone found on KL's fb of rental signs.
More information on this site.
http://www.banderasnews.com/real-estate/ownership-info.htm
This ownership situation might be something that CPS would have to go to Mexico to investigate in person with the principals involved in the the purchase, ie. in the Fideicomiso, local real estate attorney, and so on.
I'm curious to see if other posters think this is relevant.