Hi. I've only just started playing WoWs again recently and have had similar crashes (disconnects) on load screens, and only on load screens (entering or exiting battles). If I get into the battle the game runs fine until I leave. This was happening on both the NA and EU servers.
After some experimenting (that resulted in my 5 battle pink status, even though I was only doing co-op while trying to figure out the issue) I've narrowed it down to Webroot that's causing the issue. If I run with webroot protection off I don't get any DC's....as soon as I turn it on I start DC'ing every battle.
I've submitted a ticket to Webroot support, but still awaiting a reply. So if you're running Webroot yourself try turning protection off and logging in to WoWs (not an ideal solution, but it's worked for me). Strangely enough Webroot works just fine with WoT....but it doesn't seem to play well with WoWs....if anyone knows why I'm all ears.
Edit to add: Before trying webroot I did all the usual..integrity check, drivers etc. However there is a forum post about a similar issue on the NA forum, and several users have reported issues with Webroot causing the game to "hang" on load screens. Sometimes you can re-log and get in, sometimes you can't.