What happens to my own domain if I downgrade?

Your own domain and wall address are Pro and Agency features. On a lower plan they pause, and visitors are sent to your matching videoreview address, so your links keep working. Your domain settings are saved for 90 days and come back as soon as you're on Pro or Agency again. After 90 days on a lower plan, they're removed, and you'd set your domain up again once you're back on Pro or Agency.