Setup the Campaign Default as follows:

Notes:

1. Create a new Default Status with the Campaign type set to "Webinar" that we will be using. I then created three campaign status' with the first one "To Invite" set to the default status. Note the Campaign Type. We will be setting up a campaign using this later on.
2. Notice the Action is set to Replace All. This means when a campaign is used, all status’s that are not specified below will be removed.
3. In some instances, it’s best to add the various campaign status’s that are new at least once to an existing campaign before using in Campaign defaults. I.e. On the Campaign Advanced Settings Tab add there once, then setup/use in the Campaign Status defaults.

Create a New Campaign. Note I have set the type is the same as the Campaign Defaults (Webinar). This will pull all the status' and settings as the Webinar default status record.

I checked the status’. This shows expected with the three status':

I then cloned the Campaign. Keep the Type as "Webinar"

I checked the status’ as expected as per the first campaign.

i then changed the campaign to a different Type (Conference) that has the ADD/Replace option

Checked status’ Has added “Registered” and is marked as the defautt. This is as per the Add/Update status option.