Lan Wangji, a little troubled, applies himself to the folding of tamales. He hates the idea of giving Magnus false hope, but he also hates the idea that Magnus could never again see Alex.¹ It would be romantic, perhaps, to say that Wei Ying found his way back to him across the chasm of death -- but that was pure accident, the happy result of someone else's machinations. So he says nothing.

¹It's a happy dramatic irony lever moment for once!