My take on this? Of course it's going to have 1.2a adaptive sync extensions included since it's a 120hz gaming monitor. They're not talking about it because they don't want to cannibalize ROG sales with G-Sync just yet since there isn't any FreeSync monitors on the market yet. The other huge selling point is the IPS nature of the monitor.ASUS is showing the 27-inch MG279Q monitor at this year's CES, and this display features the vaunted in-plane switching (IPS) technology and a 2560 x 1440 (WQHD) resolution.
Even more impressive, this panel offers frame rates of 120Hz with a 5ms grey-to-grey (GTG) response time according to ASUS.
While officially only listing a generic "DisplayPort" input, we have learned this supports DP 1.2a Plus. What does this mean? At least on paper that would indicate that this monitor could offer AdaptiveSync / FreeSync support. We could also pretty safely assume that a WQHD monitor without G-SYNC will be priced considerably lower than an ROG Swift. It's all very interesting...
If only they made a 32 inch 4k version of this with either G-Sync or 1.2a adaptive sync.
EDIT: PC Perspective talks about this monitor
"The MG279Q is not a G-Sync monitor and is not officially a Fresync monitor. It supports 1.2a plus.....The list of monitors that were released earlier today were just the Freesync certified monitors.
If this monitor supports this standard, it doesn't need to be a "Freesync" monitor to be able to work with AMD video cards and have the adaptive refresh rate feature.
UPDATE April 7, 2014
ASUS MG279Q Monitor Now Officially a FreeSync Monitor (144 Hz)