Still ongoing. UK player, Vodafone ISP - see https://www.reddit.com/r/classicwow/comments/1aw8t6g/people_still_having_disconnect_issues/ - not just lag spikes but complete disconnects, BNet client failing to load properly, WoW/Hearthstone failing to work/login at all.
Tracing route to 185.60.112.157 over a maximum of 30 hops
1 2 ms 1 ms 2 ms vodafone.broadband [192.168.1.1]
2 15 ms 15 ms 14 ms 90.247.64.1
3 16 ms * 17 ms 63.130.172.41
4 * 17 ms 16 ms lonap-ix.blizzardonline.net [5.57.81.160]
5 166 ms * 182 ms ae1-br01-eqld5.as57976.net [137.221.79.33]
6 * * * Request timed out.
7 * * * Request timed out.