What was J. Austen saying about her society or time period by including satire in Pride and Prejudice?
What Jane was saying about society with her satire is that Society had to seriously take a step back and stop taking itself so seriously. Rank systems, marital status, heraldry, aristocracy,and all these superficial and mundane social elements that are actually just that...mundane.
With satire, Jane can get away with putting things into the perspective of the typical, red blooded citizen: She basically said what was in everyone's mind. She joked about people too romantic and platonic with Jane and Bingley; she joked about arrogant people who do it just for pretense in Darcy. She mocked the absurd obsession with the aristocracy in the characters of Mr. Collins and Lady Catherine, and she mocked the need for marriage in the character of Mrs. Bennet.
What she is saying is indeed "why are we giving importance to so much triviality?" and she made her statement effectively.
When Jane Austin wrote the book Pride and Prejudice she was well aware of the restrictions placed on the men and women in her society. She used the book to present those daily requirements of self-governing and suppressedemotions in her story and to demonstrate the harm that they may cause as well as their silliness.
During Austin's lifetime it was even rare for a woman to be able to find success as a writer. Life was about manners and pomp and circumstance. Women were expected to make a good marriage and if there was no wealth in the family there was very little chance of a woman gaining a good husband. Having a good and pure reputation was also very important for a woman of Austin's era. Men were allotted a few discrepancies such as gambling and wandering, but overall it was a relatively stiff society.