AFAIK, there is no difference in how Building Blocks work in Word in any of the Ribbon versions. That is to say that the Building Blocks
saved in a template in any of these versions will function in any of the other Ribbon versions.
There are differences in the Cover Page
built-in building blocks. There may be other
built-in building blocks differences that I haven't noticed. These should have no effect on building blocks
stored in your custom templates.
Automated Boilerplate Using Microsoft Word
Where can Building Blocks be stored?