I bought a new 6721 AR-15A3 Tactical carbine (HBAR heavy profile barrel) early in 2010 and it still had the LE restricted markings at the right side of the magwell.
Then next year after that in 2011, I bought a new SP6920 marked "Sporter M4 Carbine" which does not have any restricted makings, also the next year of 2012 got a new LE6920 marked "M4 Carbine" also no restricted markings.
It's around that time when they were phasing out the LE restricted markings on LE series carbines, the last 100 units LE6920 marked "Colt's Law Enforcement Carbine" with restricted markings even had certificates of the last 100 built with restricted markings.
But even after that official last 100 batch with restricted markings and paperwork, the factory later released some (about 100+) with the same markings of leftover lower receivers, without any certificates.
Lately I had not seen any new Colt AR models with LE restricted markings.