Yep wow has been bad, it's because of the Google capacity issues in JHB. WoW servers are a hybrid setup, some are hosted on Blizzards infrastructure and some on Google cloud, as you switch between zones and instances in-game you switch between Google cloud and Blizzards servers.
The UK VPN solves the latency and disconnecting issues, I have not had any disconnects or latency issues on wow since using it.
Using the UK VPN causes you to bypass Google's POP in JHB and forces the traffic to use CISPs transit instead of Google's