Meghan, I think you're correct that Durkheim didn't think of society as stagnant. Your observations of what society needs are spot-on, esp. regarding fluidity.

However, I'd also argue that what was commonly seen as functionalism – especially in mid-twentieth century America – has little to do with Durkheim, and more to do with social Darwinism and eugenics. It was more about maintaining the status quo – or worse, simply researching the status quo and presenting it as something that should be.

Instead, I hearken more towards the ameliorative movement, which does share a Durkheimian thread of looking at society with an aim of improving it for all peoples.