They've always repaired the USMC's optics though. The GWOT era TA31s had flush adjustment turrets that you turned with a piece of brass, and as they go back to trijicon for tritium and seals they also replace the turrets with the new external ones.

Also I believe the Marines sent the vast majority of M16A4 spec TA31s back to trijicon and had them retrofitted with brand new TA31-D-100581 spec prisms and all the above new upgrades as well. The 100581 is a one sized fits all reticle for the A4, M4 and IAR.

This is not really news they probably just renewed their contract, or the old contract ran out of funds, ACOGs just do not fail that often.