As a developer I think it's hilarious that they specify that only "third party services" are not allowed.
Nothing is stopping the streamer, as a first party, from combining chats.
Nothing is stopping the streamer, as a first party, from combining chats.
Many streamers are not technically adept. For them it would be easier to use a hypothetical Chat-Combiner-Third-Party-Service, but they are banned from that. They have to install some software on their computer (many cant), that software needs to be configured and nothing stops twich from pulling tricks ro break it. Basically they make it harder for streamers.
1st party: Twitch
2nd party: An entity Twitch has made an agreement with that lets them merge chats
3rd party: Everyone else