Refactoring test cases in Agile projects is primarily done to ensure that the test cases continue to provide adequate coverage for the product's functionality, which may have evolved or changed. This process involves revising and improving the test cases to adapt to any updates in the product's code or features, thereby maintaining their effectiveness and relevance.
References = The ISTQB Advanced Level Agile Technical Tester documents highlight the importance of refactoring test cases to align with the continuous evolution of the product in an Agile environment123.