No, it still works.
Streamlink.exe -l debug twitch.tv/. 360p
[Streamlink for Windows v2.0.0 - Git aaf8db9]
[cli][debug] OS: Windows 10
[cli][debug] Python: 3.6.3
[cli][debug] Streamlink: 2.0.0+aaf8db9
[cli][debug] Requests(2.18.4), Socks(1.6.7), Websocket(0.44.0)
[cli][info] Found matching plugin twitch for URL twitch.tv/.
[plugins.twitch][debug] Getting live HLS streams for .
[cli][info] Available streams: audio_only, 160p (worst), 360p, 480p, 720p, 720p60, 1080p60 (best)
[cli][info] Opening stream: 360p (hls)
[stream.hls][debug] Reloading playlist
[stream.hls][debug] First Sequence: 1159; Last Sequence: 1165
[stream.hls][debug] Start offset: 0; Duration: None; Start Sequence: 1163; End Sequence: None
[stream.hls][debug] Adding segment 1163 to queue
[cli][debug] Pre-buffering 8192 bytes
[stream.hls][debug] Adding segment 1164 to queue
[stream.hls][debug] Adding segment 1165 to queue
[stream.hls][debug] Download of segment 1163 complete
[cli][info] Starting player: "C:\Program Files\VideoLAN\VLC\vlc.exe"
[cli.output][debug] Opening subprocess: "C:\Program Files\VideoLAN\VLC\vlc.exe" --input-title-format twitch.tv/. -
[stream.hls][debug] Download of segment 1164 complete
[stream.hls][debug] Download of segment 1165 complete
[cli][debug] Writing stream to output
[stream.hls][debug] Reloading playlist
[stream.hls][debug] Adding segment 1166 to queue
[stream.hls][debug] Adding segment 1167 to queue