Change Ticket Product when changing username
Currently when you change your username, your ticket product (the name that appears on subscription receipts) stays as your old username. Please make it match your current username so people don't refund subs thinking they are subscribed to someone else.

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targetplayer commented
On the Subscriptions page (twitch.tv/subscriptions), clicking the Edit Subscription gear icon and then hovering over Don't Renew Subscription displays the channel's ORIGINAL name at lower left (i.e. https://twitch.tv/unsubscribe/originalname) rather than the channel's CURRENT name (i.e. ...unsubscribe/currentname) in the case of a channel whose name has changed.
Clicking Don't Renew at this point still successfully unsubscribes, but the URL should display correctly - it should be the channel's current name. This matters because if a creator used to have their own legal name as their Twitch name and then changed it to something less identifying, this bug effectively doxes them.