Not necessarily for a director to step down. I do not know specifics about Noront but have been involved in doing same with other companies.

Seven directors so each one probably represemts 14.3% of the total shares. Basicly during the next ellections for B.of D. you need at least 14.3% to nominate and ellect, or write in, a preferred candidate in the ballots. This requires a concensus before the vote of who we write in during the voting otherwise we would self defeat by cancelling each other's votes.
That is not easy to arrange.