No functional changes. Since Twitch's website is using the v2 endpoints, Streamlink should do this as well.
$ ./script/test-plugin-urls.py twitch -m -r CHANNELNAME esl_dota2
:: https://clips.twitch.tv/GoodEndearingPassionfruitPMSTwin-QfRLYDPKlscgqt-4
:: 360p30, 480p30, 720p60, 1080p60, worst, best
:: {'id': '1230765715', 'author': 'LIRIK', 'category': 'Pax Dei', 'title': 'Lirik loves Pax Dei'}
:: https://player.twitch.tv/?parent=twitch.tv&channel=esl_dota2
:: 160k, 160p, 360p, 480p, 720p, 1080p, worst, best
:: {'id': '316275755751', 'author': 'ESL_DOTA2', 'category': 'Dota 2', 'title': 'LIVE: Team Liquid vs. PARIVISION - DreamLeague Season 28'}
:: https://player.twitch.tv/?parent=twitch.tv&video=1963401646
:: 220k, 160p, 360p, 480p, 720p_alt, 720p, 1080p, worst, best
:: {'id': '1963401646', 'author': 'dota2ti', 'category': 'Dota 2', 'title': 'LGD Gaming vs Gaimin Gladiators [0-0] - TI 12 LOWER BRACKET FINAL'}
:: https://player.twitch.tv/?parent=twitch.tv&video=1963401646&t=1h23m45s
:: 220k, 160p, 360p, 480p, 720p_alt, 720p, 1080p, worst, best
:: {'id': '1963401646', 'author': 'dota2ti', 'category': 'Dota 2', 'title': 'LGD Gaming vs Gaimin Gladiators [0-0] - TI 12 LOWER BRACKET FINAL'}
:: https://twitch.tv/papaplatte/clip/SmellyDeadMomBloodTrail-WWr5gMxd0pe0BAge
:: 360p30, 480p30, 1080p60, worst, best
:: {'id': '2105975528', 'author': 'Papaplatte', 'category': 'GeoGuessr', 'title': 'fan moment'}
:: https://www.twitch.tv/clip/GoodEndearingPassionfruitPMSTwin-QfRLYDPKlscgqt-4
:: 360p30, 480p30, 720p60, 1080p60, worst, best
:: {'id': '1230765715', 'author': 'LIRIK', 'category': 'Pax Dei', 'title': 'Lirik loves Pax Dei'}
:: https://www.twitch.tv/dota2ti/v/1963401646
:: 220k, 160p, 360p, 480p, 720p_alt, 720p, 1080p, worst, best
:: {'id': '1963401646', 'author': 'dota2ti', 'category': 'Dota 2', 'title': 'LGD Gaming vs Gaimin Gladiators [0-0] - TI 12 LOWER BRACKET FINAL'}
:: https://www.twitch.tv/dota2ti/video/1963401646
:: 220k, 160p, 360p, 480p, 720p_alt, 720p, 1080p, worst, best
:: {'id': '1963401646', 'author': 'dota2ti', 'category': 'Dota 2', 'title': 'LGD Gaming vs Gaimin Gladiators [0-0] - TI 12 LOWER BRACKET FINAL'}
:: https://www.twitch.tv/esl_dota2
:: 160k, 160p, 360p, 480p, 720p, 1080p, worst, best
:: {'id': '316275755751', 'author': 'ESL_DOTA2', 'category': 'Dota 2', 'title': 'LIVE: Team Liquid vs. PARIVISION - DreamLeague Season 28'}
:: https://www.twitch.tv/esl_dota2/
:: 160k, 160p, 360p, 480p, 720p, 1080p, worst, best
:: {'id': '316275755751', 'author': 'ESL_DOTA2', 'category': 'Dota 2', 'title': 'LIVE: Team Liquid vs. PARIVISION - DreamLeague Season 28'}
:: https://www.twitch.tv/esl_dota2/?
:: 160k, 160p, 360p, 480p, 720p, 1080p, worst, best
:: {'id': '316275755751', 'author': 'ESL_DOTA2', 'category': 'Dota 2', 'title': 'LIVE: Team Liquid vs. PARIVISION - DreamLeague Season 28'}
:: https://www.twitch.tv/esl_dota2?
:: 160k, 160p, 360p, 480p, 720p, 1080p, worst, best
:: {'id': '316275755751', 'author': 'ESL_DOTA2', 'category': 'Dota 2', 'title': 'LIVE: Team Liquid vs. PARIVISION - DreamLeague Season 28'}
:: https://www.twitch.tv/lirik/clip/GoodEndearingPassionfruitPMSTwin-QfRLYDPKlscgqt-4
:: 360p30, 480p30, 720p60, 1080p60, worst, best
:: {'id': '1230765715', 'author': 'LIRIK', 'category': 'Pax Dei', 'title': 'Lirik loves Pax Dei'}
:: https://www.twitch.tv/videos/1963401646
:: 220k, 160p, 360p, 480p, 720p_alt, 720p, 1080p, worst, best
:: {'id': '1963401646', 'author': 'dota2ti', 'category': 'Dota 2', 'title': 'LGD Gaming vs Gaimin Gladiators [0-0] - TI 12 LOWER BRACKET FINAL'}
:: https://www.twitch.tv/videos/1963401646?t=1h23m45s
:: 220k, 160p, 360p, 480p, 720p_alt, 720p, 1080p, worst, best
:: {'id': '1963401646', 'author': 'dota2ti', 'category': 'Dota 2', 'title': 'LGD Gaming vs Gaimin Gladiators [0-0] - TI 12 LOWER BRACKET FINAL'}