I am sure someone from Twitch Legal would need to contact you but I read this:
Inappropriate & Appropriate Commercial Uses
The following activities are prohibited, absent a separate agreement with Twitch:
- Selling, licensing or otherwise distributing any metadata or social content or authorizing access to any metadata…
As a no go if you are selling the data. You would need to work with Twitch I assume, reading that, and get a separate agreement written up.