Plus, there's that issue of they have to restore the herbs if they're still going to adhere to the tradition involved with the successor becoming Black Panther. The Wakanda book implied Shuri is on the verge of a breakthrough with the herb and has some ideas on modifying it, too. It's an interesting predicament, since Shuri is next in line but if she declines becoming the next Black Panther, barring any other cousins, who is next in the line of succession?