I would say this is "expected" but unfortunate.
CMAA is a post-processing anti-aliasing technique - if it is on, it will detect color gradients as edges and try to "smooth" them. This helps get rid of jaggies in games but if applied to things like text can make them blurry.
The driver automatically ignores the forced CMAA setting for applications like browsers, the Windows desktop, etc. Unfortunately, the list of excluded apps doesn't include Office at this time. See release notes from when the feature was first added:
To reduce the probability of unintended blurring, certain applications are automatically excluded from the support
list: Windows* explorer, login screen, Windows* home screen, Internet Explorer*, Google* Chrome, and Firefox*
browsers, and the Windows 8.1 Photo application”
As a result, in general, it should ONLY be enabled via control panel before launching a game issue where you want to use the feature and then turned off in the control panel.