iris.to client provides a feature to delete posted content. Does this mean that I have complete control over the data?

I have confirmed that when I write a post, it receives a unique noteID value. Additionally, I have noticed that by copying and pasting the noteID, I can directly access shared records and JSON-formatted data on various clients such as nostr.com, iris.to, and primal.net.

When I clicked the delete button on iris.to, the post was deleted, and for a while, I could only see it on nostr.com. However, after a few minutes, I couldn't find it on nostr.com either.

Does this indicate the complete deletion of the data? I'm curious if it involves deleting the shared JSON-formatted data field. If anyone has knowledge about this, please provide an explanation. Thank you.