I think that one way in which the thesis about excess and unacknowledged servants could be enhanced would be by mentioning how none of the servants occupy a very important role in the narrative. Those who serve do not receive much in way of acknowledgement through identification. The people like Tom, Daisy, and Jordan do not really acknowledge "the help." This is a part of the 1920s social scene that is vitally important to Fitzgerald. The entire premise of the social world of the 1920s is built upon a foundation that is not acknowledged and not recognized. It is seen in the idea that this world is built upon a "promise that the rock of the world was founded securely on a fairy's wing." The weakness and fraudulence of such a time period is displayed in how the luxurious excess of the 1920s lifestyle was dependent on the labor of unacknowledged servants.
The idea that those who toil the most receive the least of the reward can be seen in how the characters in the novel recognize workers, or those who labor. Myrtle echoes this when she derides those who serve:
"I told that boy about the ice." Myrtle raised her eyebrows in despair at the shiftlessness of the lower orders. "These people! You have to keep after them all the time."
It is interesting to note that Myrtle, who really does serve Tom, appropriates the attitude of the upper class towards servants. The need to "keep after them" all the time and in how she refers to him as "that boy" represents how the world of the 1920s was built upon the labor of unacknowledged servants. This same element is seen in how Nick notes that "on Mondays eight servants, including an extra gardener, toiled all day with mops and scrubbing-brushes and hammers and garden-shears, repairing the ravages of the night before." Nick recognizes the fact that unacknowledged servants construct the world of luxury, celebration, and revelry. It is in this light that Nick makes the astute observation about Tom and Daisy, as well as life in the 1920s, in general:
They were careless people, Tom and Daisy--they smashed up things and creatures and then retreated back to their money or their vast carelessness, or whatever it was that kept them together, and let other people clean up the mess they had made...
In the end, unacknowledged servants were the "other people" who had to "clean up the mess they had made." This carelessness is a vital part of the 1920s world that Fitzgerald creates.