Many fairy tales are. Especially the oldest. Some of them have direct references to historic people. This is what I got out of the story:

I think the sausage is supposed to be the rich class, safely hidden away, in a life of luxury, having others do most of her work. Leaving the safety of their own land without protection was no safe task for many nobles, especially with warring nobles around waiting for a chance to seize more power. With an excuse, the dog took out their neighbouring queen and left society to crumble.

The mouse may be an allegory for the church (as the church, nobility, and the laymen were often grouped together). Though the sausage clearly had an easy life, the mouse had control in the end, and could be persuaded by the bird (the common people doing the hardest work). The second bird was a (foreign?) revolutionary, infecting the bird’s mind with dangerous ideas.

In other words: stay in your lane, just do your chores, and everyone is better off. Start shit and society will collapse, and everyone will suffer. Probably written by someone well off.