Any prior expansion? Probably not, but only because things weren’t as bad as they are now. Even with the Horde pushing through Ashvenvale in cata they never got as far as sieging Teldrassil let alone destroying it. The last time the Nelves suffered a lost as tremendous as this one the world was shattered, and with how hard they’ve fought to protect Azeroth since then having a moment of wavering devotion when your goddess at best soothes the dying as they burn seems reasonable.
Elune not rebuking Tyrande also seems pretty reasonable, because at the end of the day what does she have outside the night elves? If she rebuked Tyrande and let the nelves perish or forsake her then, to again bring up the Azshara cinematic, she’d be the goddess of nothing.