The % Allocation / Default Allocation % field in the column list views is the Default Allocation which is not a calculated field (it is an editable field). The field that is automatically calculated is the Average Allocation % field. That one would be updated based on allocation changes. See KB000052381
for details on how the Average Allocation % field is calculated.
To add The Average Allocation % field to a view (example below for the Team Staff View):
1. Got to the Team tab of a project
2. Click on the Options icon (Gear icon) on the right hand side
3. Click Configure
4. From the 'List Column Section'->Layout, in the 'Available Columns', select the Average Allocation % field and move this to 'Selected Columns'
5. Click 'Save and Return'