"Tell me, son of Lily, do the Muggles in their wisdom say that soon the skies will be empty?"

Interesting tie-in to:

"HE IS HERE. THE ONE WHO WILL TEAR APART THE VERY STARS IN HEAVEN. HE IS HERE. HE IS THE END OF THE WORLD."

So the centaur and Trelawney seem to be reading from the same playbook. Any guesses to who the centaur approached sixteen years ago and what lines he crossed? Seems like a plausible time to be Lily, no? Could possibly be the payoff to this from Chapter 1:

"...And I begged her to use some of that magic on me so that I could be pretty too, even if I couldn’t have her magic, at least I could be pretty.”
Tears were gathering in Petunia’s eyes.
“And Lily would tell me no, and make up the most ridiculous excuses, like the world would end if she were nice to her sister, or a centaur told her not to – the most ridiculous things, and I hated her for it."