The TEXTJOIN() function combines text from multiple ranges with the added flexibility of a specified delimiter.
Use CONCAT() to combine multiple strings or ranges similar to TEXTJOIN(), but without the flexibility of a delimiter or empty argument.
The IFS() function checks one or more conditions and returns a value that corresponds to the first TRUE condition.
SWITCH() MAXIFS() MINIFS follow similar themes.
I bring these up as it is good to know what the successful office 365 products are upto. Also be very aware that Excel 365 is a different beast to Excel Desktop. VBA programming is the standout biggest 365 omission.
I recommend trying the free versions of IOS or Android Excel just to get a feel for what is happening in that space. It is a guarantee that you will run into someone who converts to Office 365 and needs help.