I don’t like Gleason or nostr but this happened with mostr too lol, people were getting real up in arms accusing it of duplicating accounts, going so far as to DMCA the project. but that’s literally how federation works, any account or post that’s federated is cached on the instance lol. it’s like people don’t realize that their public posts are public
nostr relays can comply with delete requests or not, same with fedi servers. pretty sure they all do though and relays don’t share posts with each other. there’s a couple of crawler services like nostr.band and noswhere for search and indexing, but if you delete your fedi post or don’t post publicly it should be gone from mostr