One of the long-awaited features was recently added to Excel in the latest Office 365 update, which is the code completion (IntelliSense) and syntax coloring that was added in the Custom Column Editor and the Advanced Editor. In addition to other features in the Advanced Editor such as Display line numbers.
You can use these features if you have the latest Office 365 update:
It's recently added the stable production channel (Monthly Channel) which is the intended channel when we just say Office 365.
Yep, it's been in the insider (Monthly Targeted) a while ago. but since the major Office 365 users are on the Monthly Channel, it is better to delay talking about it until it reaches the stable version.