Hello,
I will submit this suggestion for you, that ninjas move to coupon purchase faster. Thanks and have a great day!

I apologize for locking this thread without directly responding to your questions.

I closed it because I thought the matter was settled when I submitted your suggestion. I had thought that most of your post was just you venting, not that you actually wanted answers to your questions. I apologize for that mistake. In answer, then, while I didn't research your claims as thoroughly as you claimed to, I know for a fact that at least some of them are mistaken. Multiple new outfits, at the very least, have been available for coupons. You are correct that AS Itachi has been paygated for the entirety of his release, but that is unsurprising considering the price points he was released at and the value the devs seem to place on him. I would also point out that "not a single new ninja release has been made available for free except the useless ones" is a somewhat biased view point. Of course the better ninjas will be slower to come to coupons, while the not-as-better ninjas will be faster to come to coupons. To qualify your statement as "All the things past this threshold didn't do this" is to deny the existence of a meaningful threshold, but that threshold is quite literally the delineating reason behind the answer for your question: Some ninjas do indeed transition to coupons.

I am sorry that the ninjas you are specifically interested in have not been readily available for you, yet. It is my hope that they become available in the near future. As always, you are welcome to create a thread asking for those ninjas to be made available in events, or to post a suggestion in the official discord, if there is a specific ninja you would like to see get a faster treatment. Thanks and have a great day!