Let's talk about... everything else
Not very long, better to claim them sooner than later.
You have exactly 7 days from the moment they dropped. Which means you barely have until tomorrow or Sunday, maybe less, you need to check them:
The expiration date was announced almost a week ago on the forums, on social media accounts, on Discord, on the Twitch-RoR user page and on the very own game client you use to login ^_^
Correct, when we push the Twitch Drops access to the respective channel (for the event period), you read the "Drops Enabled". If you check a channel that hasn't been approved, or if the event hasn't started, or if the event has ended, you will not read "Drops Enabled".