In general: No.
When a datafeed runs, the profile field values for each user are read from the datafeed file, and populate for each user automatically, with the following exception:
Hierarchy fields: Yes.
Profile field values of the Hierarchy type must be mapped in the Hierarchy Tree before the datafeed can handle them. Any Hierarchy type values in a datafeed file without a corresponding mapping in your Hierarchy Tree will be discarded.
Note: See the article: FAQ: Do I Need to Manually Create Values for a Datafeed?