No I did not say it was you but someone else said something about they did it to cool the electric coil as I was refering to them about that.
From a technical standpoint you are right as of course it needs atmosphere on one side for the vacum (low pressure area) to really work since really atmosphere pressure really pushes rather then vacum (low pressure) pulling on anything. But I really dont think that choke cap is sealed that well where the pressure/vacum would even out on both sides of the choke piston so it would not work. All of the carbs like this that I have worked with over the years are the older ones that do not have an electic coil on them as they all used the coil heated by hot air and the vacum that leaks past the piston to pull the hot air into the choke housing. I have not really fooled that close with many of the newer Eddy carbs like this one that use the electric choke with the housing and piston on the carb as this one. The ones I have fooled with are like the ones my brother uses on his dual Eddy carb setup as most Mopars that use well type choke coil and the external vacum break diaphram. But I do agree with you as with any vacum anywhere you need to have atmosphere pressure on the other side to work and the older ones all did since they used the atmosphere pressure side to feed the hot air to the choke coil since the choke piston is not sealed real good in its housing and the vacum leaks past the piston. Ron