I would solve it like this:
- create a segment called “do not contact marketing”. Exclude this segment from all other marketing segment. Maybe set filer for “do not contact marketing” tag
- create a segment called “unsubscribed” where you filter for everyone who sets do not contact via unsub link.
- create a campaign, which starts with the segment you just created in step 2.
- remove do not contact
- add to “do not contact marketing tag to these people”
When you send marketing, make sure you exclude “do not contact marketing”
Good luck to you!