Hello,
Fireworks Festival gives out ninjas of a very specific price point, specifically free ninjas worth around 8k - 12k coupons that are outside the high-end meta.
Halloween Kimimaro is an extremely valuable ninja that is still a part of the current meta and does not fall into the category of what an acceptable Fireworks Festival ninja would be. In the past, we only received 40 fragments of an old meta ninja (Angel Konan). We would be lucky to receive even 10 or 20 fragments of a current meta ninja, much less one as useful and powerful as Halloween Kimimaro.
This is a great free reward for new players, returning players, and free players, and it makes sense for the holiday. Halloween Kimimaro is far too valuable and expensive a prize to expect for free.
Thanks!