My bad, I did some digging this morning and it seems that I was mistaken. I popped open the catalog and price list for this year and every LE model in the catalog has an LE serial and Colt Defense on the lower, except for the LE6920MP-R, and the LE6920SOCOM. The strange part is, when you look at the 6720MP-FDE it got an LE rollmarked lower with Colt Defense on it.
I knew the MP-R had a mess of extra stuff stacked onto it, but in the manufacturing process usually companies mass-manufacture parts according to series and they get serial numbered based on that series, then they get sent to the various other production lines to get fitted with accessories to finish the product. The SP serial number he has is a standard format for an SP lower, and the Colt's MFG Co. stamp is typical of their consumer model product. In the past, the LE's standard format is LE serial and Colt Defense upper, and was the standard on their military/LE product. I (incorrectly) made the assumption that a serial of SP meant "Sporter", which was always sold as the "civvy" model of the LE.
Basically colt is putting an SP upper and lower with magpul parts and calling it an LE, but it's not coming off the same line as the LE, or it would be stamped & serial numbered the same as the other LE products they produce. It should be, logically, identical to an SP with magpul parts, despite being packed as an LE model. Since only the upper and lower are made by Colt, and TALO is putting the troy rails & magpul parts on it, I would assume TALO was sent SP stamped & rollmarked complete rifles and that they let loose and do all the rest of the assembly and finishing.
I guess at the end of the day, colt doesn't care which serials or rollmarks made it onto the product. The catalog is a mishmash of LE and SP marked lowers on all the LE product. All the MT product has the "Colt's Mfg Co" stamps, but that seems to be the only constant in the catalog.
I'm sure whatever they are doing, it was to increase efficiency and profit to insulate the company from uncertain times, both in the states and around the world.
I apologize for the ignorance.