I believe he means that in 2012 it wasn't legal when the person wrote that article, as the ability was not available yet while in DW OU it was available, and was eventually made available in OU
The only way to know for certain would be to go look for the threads that these analysis were posted and look at the dates.
I did some digging and according to this
post dated December 28th, 2011; the HA for the entire Swinub line hadn't been released via official event or PGL and the 2012 season began in November of 2011
