Only songs/spells that were available during classic are purchasable. The NPC's that vendor this song are not even in game yet.
Wut? This is a classic spell that is sold in Erudin. The NPC is up and selling all the other ones, this one is just missing. This is an issue that goes back at least as far as Fippy/Vulak, and likely all the way to Combine/Sleeper. https://forums.daybreakgames.com/eq/index.php?threads/shield-of-songs.184261/ . So it isn't like it got removed on purpose along with Breeze.