What a shocking story. I'm not familiar with NB (although I've heard other writers mention the name) but this seems to illustrate a perennial problem on platforms across the board - contributors are at the mercy of any changes in the algorithm that the platform directors choose to make. Even so, I cannot see what NB has to gain by alienating so many of its writers. Hopefully it's a blessing in disguise for you, having brought you here to Medium :)