https://gamestoday.info/pc/world-of-...of-the-tauren/ this source also seems to have some good exerpts from the book providing context.
----------------
"Baine felt as if his own core were molten with outrage. It was with the greatest of efforts that he had kept from exploding in anger when Malkorok had challenged him. He was not afraid Malkorok could defeat him—by all accounts, Cairne had been winning the battle against Garrosh, before Magatha’s poison had claimed him. Baine bore his father’s blood and he had youth on his side. No, he had declined because there was no way to truly win. Poison would be used again, but better hidden this time. Or even if he slew Malkorok, there would be an ambush waiting in the shadows. And then, what would happen to his people? There was no clear successor yet. Garrosh would somehow see to it that a tauren was appointed whose thinking was more in line with his own—or who could be persuaded to think so.
No. His people needed him alive. And so, Baine would live, and do what he was ordered to do. Exactly, and only, what he was ordered to do."
----------------
This one's huge as a reference to "hurr durr why doesn't he just mak'gora Sylvanas?" Hell, at this point I wouldn't put it past her to kill him, raise him as a mindslave like Derek, and plop him right back on the throne.