What is the meaning of the last two lines of Auden's "The Unknown Citizen?"

In my opinion, the last two lines of the poem serve to point out quite explicitly the theme of the poem.

I believe that this is a poem about how the modern world has served to dehumanize...

The politicians of every nation express their respect and honor perfunctorily to the memories of the martyrs who had laid down their lives in safeguarding the country by building an impressive monument dedicated to the 'Unknown Soldier,' and visiting this monument occasionally to place a wreath on it. This is a charade which became popular especially after World War I.

Auden's ironic poem "The Unknown Citizen" sarcastically suggests that the anonymous ordinary citizen also deserves a similar monument for conforming exactly to the rules and regulations of a mediocre modern civilization. Just like how the monument of the 'unknown soldier' will never reveal the true feelings of the martyrs who sacrificed their lives in serving their country, the modern state will never know, leave alone care whether the 'unknown citizen' was free and happy:

Was he free? Was he happy? The question is absurd: Had anything been wrong, we should certainly have heard.

The poem is a bitter satire against  modern forms of government whose only aim is that all its citizens conform to its sterile norms. The  'unknown' citizen who is only given a number - JS/07 M 378 - sacrifices his unique personality  by abiding by the norms of the state to 'serve the Greater Community.'  By doing so he is canonized by the state which honors him with a marble monument!

In the modern setting, government bureaucracy is more dominant than anything else.  Even in the most liberalized nations that are predicated upon a theoretical notion of individual freedom and...

The last two lines show that this is the governments picture of a perfect citizen not anybody elses