Microsoft has rolled out a fresh new update for users in the Preview Build of Office Insider Program of Android. The latest build version is 16.0.11231.20010.
This is a preview of the January 2019 feature update which brings new features for Word, Excel & PowerPoint Apps. Check out the full changelog below.
Changelog:
Get their attention with @mentions
Use @mentions in comments to let co-workers know when you need their input.
New in: 
Collaborate effectively with comments and @mentions
Keep the conversation going right in your worksheet with the built-in reply box and let co-workers know that you need their input by using @mentions.
New in: 
