Hello,
Taka Suigetsu only debuted one month ago, so he's not likely to see a Fukurokumaru deal next week. Kushina debuted two months ago, so this is a little more realistic, however, both units have only recently become available for purchase using coupons. Following the trends of other units, they need to spend some time being purchasable for coupons before they are eligible for a Fukurokumaru's Deal. New Year Hashirama being a recent Fukurokumaru Deal had him arriving a bit early. Usually ninjas take a bit longer than this to get to Fukurokumaru's deals, though, again, it is possible for Kushina.
Therefore, I can make this suggestion for you, but it is unlikely, though not impossible, that it will be implemented. There are more likely ninjas that will likely see a Fukurokumaru's deal before these two, including repeat ninjas.
Thanks!