Heroic t14 ones do.
I imagine it's just a problem with how upgrades were implimented.
16/04/2013 13:10Posted by VanitasIs it intended that you aren't able to socket upgraded gear prior to 5.2 with the legendary Meta?
Yes, it is intended that you can't put the legendary meta gem on an upgraded 496 helm, but the developers are currently discussing how upgraded items may behave down the road.
No promises or any specifics we can share at this time, though.