If a large amount of unused receiving addresses were accidentally revealed (say 50 or so)
You can produce millions of "unused" bitcoin addresses per second. There is nothing to reveal here, addresses are just hashes and they neither pose any security risk nor any privacy risk. Addresses, similar to public keys, are meant to be "public".
Even if the addresses (the 50 you said) is from a wallet it still only poses a privacy risk since those addresses would be linked then.