Suppose we have deployed a wsp (say webpart) with a feature at site collection level and it is activated.
Then, we change code of the webpart, create a new wsp.
Then, go to central admin->manage farm solutions-> retract and remove the wsp.
Then, install the new wsp using PowerShell - Add solution and PowerShell - Install solution.
Will the webpart get updated, because we had not deactivated the feature earlier, it throws error in PowerShell when we try to enable it as it is already activated at scope of sitecollection.