I encountered similar issue recently, where my date column contains blank and null values. SSIS seems to struggle with Excel date columns that contain blank cells and throws "The value could not be converted because of a potential loss of data" error when you try to convert the excel column to date [DT_DATE] format as SSIS data flow output.

My work around is disabling the error outputs on these particular date columns. Right click the Excel source in your data flow -> Edit. Find the date column that is anticipated to contain null values. Under "Truncation" tab, set value to "Ignore failure".

Ensure your table destination accepts null for date value.