@PDunn - How did you add the Word document? From your screenshot, it looks like you have uploaded a Word document to your board, making the document in your board independent of your OneDrive document.

I just did the following:

Selected a test Word doc:
 

And now I have linked document on my board, with an update button:

You can read more on the OneDrive app integration here → https://help.miro.com/hc/en-us/articles/360017731273-OneDrive