It should be noted that DMCA is NOT International and strictly a USA thing not really recognized by international law. It is however a extention of the World Intellectual Property Organization (WIPO) as interpited by the USA. That being said I belive that Twitches respect and use of it could be better improved if the WIPO was taken in to consideration instead of the DMCA.
Note this is does not mean dumping the DMCA as the WIPO is that at it's core. I am only noting this as Twich deals with a international market, which the DMCA never took in to consideration, but the WIPO does. Other mediums like Netflix, YouTube, HULU, Disney+, etc all use policies based on the WIPO and not the DMCA as they recognize they have a international audance. It is likely time for Twitch to acknowledge this and do the same.