Microsoft recently announced plans to eventually stop the activation of Silverlight, Shockwave, and Flash content in Office 365. This is not just the developers disabling bugs with an option to click a link or button to look at content. Within a few months' time, Flash will be gone from Office 365 for good.
Flash to be stopped in Office 365
OneNote excluded from Office 2019

The Universal Windows Platform (UWP) version of OneNote will now be the only app available for Windows 10, as Office 365 and Microsoft Office 2019 will do away with the 32-bit desktop app.
Microsoft's OneNote desktop application is nearing the end of its journey, as the software giant will stop developing the product line past the 2016 edition.
Make the most of Office 365

Out of the hundreds of Office 365 tools available to you, you’re probably using only 10-15% of them. This could be due to a lack of training or an unfamiliarity with some of the advanced options available in Word and Excel. But it’s easy to optimize your Office 365 investment by learning more about the following communication and collaboration features.
What Is Single Sign-On and Who Is It For?

Everyone hates making passwords. From complexity requirements to minimum lengths, each new account brings its own set of headaches. If this problem is reaching a boiling point, Single Sign-On (SSO) solutions can help. They’re secure, easy-to-manage, and do away with the need to manage a long list of usernames and passwords.
Microsoft updates Office 365 apps for Apple
Understanding Office collaboration tools
Office 365 Update: New Tools You Need To Know

Enriching Office 365 with more everyday AI functionalities, Microsoft has introduced ‘Insights Preview’ to MS Excel, ‘Acronyms’ feature for MS Word, and a Text-in-image search feature to help its users to do their best work. Learn more about the recent upgrades to Office 365 products and the new Microsoft Whiteboard Preview app in this article.