Twitch uses AWS to encode video, so the IPs may be identified as Twitch even if they're actually assigned to generic AWS address space. That's by best guess, I highly doubt this is a case of malicious abuse.
Right so the ISP should saw AWS like it does for other streamers on Kick, except for XQC (checked like 2-3 other streams). How come it says Twitch on XQC's stream and AWS for the other streams?
Twitch doesn't own any streaming infrastructure, it's all cloud providers. If it's being labelled as twitch it's because twitch dominated that subnet of their cloud provider for a while.
You should consider that "looking the ip up" is really just asking some random company what they think the ip is.
Good answer and I'm using Maxmind for this.
I wasn't aware that they would record ISP changes just because one of their clients was using their IPs a lot and I thought this would only happen if you register the IP on your own ISP (similar to how you purchase dedicated IPs and register them on your own company).