i just pulled a choke assembly apart. that hole/passage doesn't connect to the vacuum port of the carb or the suction side of the choke piston. i believe it to be a relief port (probably backfire relief) for the body of the choke assembly. if the assembly is carefully looked at you'll even see a small screen in the relief passage. it's supposed to be the way it is.
Here's one I pulled off an Eddy. OP, I don't need this- PM me if you want it. It has no hole. And that passage is connected to the inside of the choke housing.
Edit- couple of pics of AFBs with heat tube fittings in that spot. Cold air to cool the electric coil? I'd prefer no vacuum leak.
