Hi,
I can confirm that the forum is still visible to others.
If you did click on the "Yes, delete xxx forever" button after selecting the delete option then I can only assume that Nabble holds the request for a short period, perhaps up to 24hrs, and then makes the deletion during an overnight housekeeping process.
If you fully completed the delete process and it's more than 24hrs ago then I can only suggest you try again and hope it works next time.
Volunteer Helper - but recommending that users move off the platform!
Once the admin for GregHelp now deleted.