Usually the focus on ninjas in events are new ninjas or ninjas that have not been in events for a long time. Masked man and jonin minato have been events for months consequently. I assume they are on hold while other ninjas are allowed to be in events. You can make a suggestion for them to show up here since doing in General Discussion is the not correct way: https://forum-narutoen.oasgames.com/page/show-thread-39-1.html

I'm not referring to the RNG events. I'm talking about events where you can redeem fragments. He was frequently in events but because of the new ninjas, it seems he's on hold.