Split from this thread.
We've also started experiencing this issue. There were no problems with version 16.0.9029.2167, however the issue appeared once we upgraded to 16.0.9126.2109.
The emoticons appear as a blank text field as the OP mentioned. However we also have an issue where any block of text will also be blank/does not appear at all.
In the screenshot I've attached, the blank text box was a :) emoticon, I then typed 'test2' which appears ok, I then types 'test3 :)' which does not show at all.
We are running Office365 click-to-run.