In order to make meaningful historical comparisons of your data, it makes sense to have data from a discontinued ad account or ad platform archived in your Funnel account. If you're no longer advertising on a specific platform or using a certain Google Analytics view but you want to keep the historic data, all you need to do is select the "Pause downloads and mute warnings" option.
This will disable any errors for the connection you want to "archive", which can be helpful if Funnel is prompting you to reconnect an ad account that is no longer active
or you no longer have access to. If you wish to resume downloading at a later point, simply select "Resume downloads".
There is also the option to exclude a Data Source from being used in Funnel. You can read more about this option here.