Since Microsoft’s patch naming can be ambiguous, “MSO 15.11.2” typically refers to a version number increment for (MSO.dll version 15.0.xxxx) or a specific hotfix for Office 365 Click-to-Run builds. Based on the pattern, I will treat this as a security and stability update for Office 2016 / Office 365 ProPlus channel.
Example: typical enterprise testing checklist Mso15.11.2patch