Preview of Dynamic Arrays in Excel

Thanks JoeMcDaid. I think the confusion, at least on my part is why does this happen?

• Create formula =INDEX(tblCalendar[Years],Settings!C1) in Insider build. Stays like that. It works without SINGLE()
• Create formula =INDEX(tblCalendar[Years],Settings!C1) in other build, it works in non-insider build. When opened in Insider, it is wrapped in SINGLE(). Saving, closing and opening back in non-insider build SINGLE() is gone.
• In some cases, the non-insider build is converted to a CSE funtion ={INDEX(tblCalendar[Years],Settings!C1)}

I know this is a transition issue, but it will actually last years as there are people with Excel 2013/2016/2019 that won't get this until they either upgrade to O365, or get Excel 2022 or whatever the next perpetual license version is.

It would be clearer to me if SINGLE() was required to get the function to work properly in the new Dynamic Array calculation engine, but in every case I've seen with my workbooks, the addition of SINGLE does nothing except perhaps render the function as an error in non-insider builds. I have more than one workbook in our org that I cannot open in the Insider build as it trashes a pretty long formula in a table (so it changes thousands of records) for use in any version that doesn't support Dynamic Arrays simply by wrapping it in SINGLE().