If you don't use aliases, yes. But in Nostr, your key is always receiving something. Since the public doesn't know if it is a valid message or noise, you can't see the sender and even the time is unreliable for time-collision algos, it's a simple scheme that's truly powerful. 

You can always add new keys to it, if you want more privacy, but all algos that I have seen make it worse by leaving extra breadcrumbs in Nostr to be found and broken into.