I just downloaded RepG 40 - Sailfish r003 for the Mac and Extruder Hold is still there. Â It's on the "misc" tab, left hand column,Â under "platform preheat & override temperture". Â You will only see it if your machine definition is for "makerbot4gsailfish" and the bot reports a firmware of 4.0 or later.
Since I built those RepG 40 - Sailfish packages, I'm confident that they are all the same source. Â The Windows and Linux versions should be no different.