The svg looks properly anti-aliased to me, and the dashed bits of the icon might just be too small to delineate (the circle in the Group Create icon is larger).
I went to Group Create SOP help page, downloaded the SVG and indeed the dashes are bigger. I guess it's quite the balancing act when doin icons specially anti-aliased ones.
Since my Group icon is smaller I also had to increase the size of the dashes and now sort of looks like intended.
Not sure if this is related… am seeing my HDA icons getting “crushed” (gamma?) and not matching the original jpg. Using the same source image in the “help” menu of the HDA looks fine, though.