What point is Orwell making about the role of communication in Soviet society with the ultimate change in the 7 commandments?

I think that Orwell is making the fundamental argument
that communication and information can become tools of those in the position of power to
consolidate their power.  Squealer becomes the critical figure in this understanding. 
As Napoleon increases his hold on political authority on the farm, the rewriting of both
commandments and historical narrative is a means by which he can solidify his control
over the animals and ensure that his authority is legitimized.  Squealer's role as the
state sponsored media is essential in this process.  Both Napoleon and Squealer
understand that the ability to "spin" or manipulate public perception in their favor
enables them to do more than if they allowed the animals to think for themselves. 
Orwell is suggesting that individuals have to look beyond government platitudes and
information and fully understand what those in the position of power hope to gain in the
attempt to gain control.  In this light, communication is seen as a political element,
something that directly relates to power and those who have it.  It is at this point
where communication becomes synonymous with propaganda.