Yes, your custom domain is released when you downgrade to the Free Plan, and any other coach can claim it while you are gone. FITR cannot hold a domain for you or reclaim it from another coach.
If your custom domain is important to your brand, the safest approach is to stay on the PRO Plan to keep it reserved.
π¬ Contact Support if...
You have questions about your custom domain before downgrading
Email: [email protected] | Live chat: Available within the FITR platform