VLOOKUP Annoyance

***edited 5/22 to remove typo***

There isn't a way to turn this off at present without removing the cell links. The functionality is there to make sure that people viewing or modifying the cells in question know that the cell contents is linked (that is, another sheet is relying on the data in the cell).

The flyout also gives the viewer a convenient way to visit the related sheet or to remove the cell link (you need to have Editor- or Admin-level permissions to the sheet to do this).

You can find more about this expected behavior here:  

Cell Links: Consolidate or Maintain Consistency of Data

https://help.smartsheet.com/articles/861579-cell-linking

All that said, I can see that if you don't intend to modify anything (or are aware of the relationships), this information in this format could be distracting.

If you're interested in describing your use case in more detail in the form a product enhancement request, please use the "Submit Product Enhancement Request" link under "Quick links" here in Community.

Thanks!