I am running Win10, Version 1809, Home, 64-bit and just tested with Word 2010 and Word 2016.
Narrator will not read document text in Word 2010, but will read it in Word 2016. This is really not surprising, as Microsoft is not going to try to reach into the wayback machine to ensure infinite backward compatibility between Narrator, which came on the scene with Windows 8, and versions of Office that far predate that OS.
If someone has Word 2013 it would be interesting to know whether Narrator works with it. This was the first version of Word that has a "look and feel" that's very similar to that in use today.
Brian - Windows 10 Home, 64-Bit, Version 1809, Build 17763
A great deal of intelligence can be invested in ignorance when the need for illusion is deep.
~ Saul Bellow, To Jerusalem and Back