You found a secret!
As of 2/21/24, I now have 6 TamaNOTchi in my care, one for each species and gender variant- my collection is complete, unless more notchis are introduced to the world one day.
You may be thinking to yourself "Wow, Noa! It's pretty impressive that you didn't get any repeats!" Well, you'd be wrong. Thankfully, for every repeat I got, I was able to send them out to be adopted by someone else in the world, where they'll be well taken care of. However, I did hold on to their numbers for a bit, so I could make this little secret dedication, to every virtual pet who just wasn't meant to be. I considered calling them "the rejects" but that seemed mean, the important thing is that they all have homes with other users and I wish them well!! Since you're here, why not give them some treats?