Generally speaking, (personally) I think of a Go/NoGo gage as being something I try to fit a part into, say to check the diameter of a shaft. So the Go gage should be slightly larger than the shaft, and the No Go gage should be slightly smaller than the shaft.
I've never seen (in my limited experience) a Go/NoGo being used for checking hole sizes, but don't see why it couldn't be used. You would, of course, need a bit of a taper to ease entry into the hole. And of course, in this case, the Go gage would have to be slightly smaller than the desired size, and the NoGo gage slightly larger then the desired size. Hence the confusion.