I did receive:
Dragon Kite Pet
Cenarion Hatchling Pet
Swift Windsteed Mount
Goblin Weather Machine
I did not receive:
Perpetual Purple Firework
I can confirm that I have claimed the drops on Twitch
I can confirm that I have my Twitch account linked on my Battle.net account management page
I can confirm that I have waited 24 hours
Sorry to hear that you didn’t receive this drop. I’m afraid that it would now be too late to reinvestigate your account after all this time (this specific drop happened between Dec 13th and 28th). I see that you created a topic on February 9, which was probably too late for this one as well.
Please do make sure that you contact us as fast as possible if you believe that you encountered an issue with the game.