Idea placed on behalf of my end users.
It appears that Tableau changed functionality for the “Data Source Time” field. When using a Tableau Server data source, the field no longer shows the date/time of the data source refresh and instead treats it like a live connection to the underlying data, showing the current timestamp. This is misleading report users into thinking the data is actually live.
Return the field back to its original functionality.
From this appears to be a conscious "feature" change.