Why doesn't the column view of a user defined field automatically update when amended in the Data Center?

Essentially changing the name of a UDF in the Data Center is not expected to update the respective column name in the list view. This is expected due to the design of the column names being saved as part of list views (to support things like custom names). To adjust the current column view it is expected to re-name the column to the field name entered within the Data Center.

You may inactivate a UDF and then add a new one versus changing the name of an existing field to ensure the column name is correct.