Hey there,
EU has been active for some time now when it comes to people that are actually considering themselves "twinks". What we do lately is try to snipe each other for better games, since stomping levelers can get rather dull in the long run. Some of us experienced twinking when it was at its peak. What I mean by that is that twinking was 10 times more competitive back in WoD because of the separation of levelers and people with locked EXP. This meant that twinks only faced other twinks, making the games a lot more interesting. This is why we now make groups of 5 on each faction and try to snipe each others groups. We also do 10v10 wargames from time to time, which is a lot of fun. (would be better if flag stacks worked as intended though).
It's funny that you got the expression that US seems active in the 19s scene. It has been inactive for quite some time now. I believe the most active bracket on US now is the 20-29 bracket. However, in the past, US has certainly been more active than EU. And whenever a new tournament is hosted, then there is still a high chance for that tournament to be based on US servers. This is simply due to history and the activity US used to have, and that we lack event-makers on EU.
As for servers on EU, we have a few servers that seem active when it comes to twinking. Outland alliance, Ravencrest alliance, Stormscale horde, Aggramar horde/alliance and Draenor horde all seem fairly active at the moment.
I'll be on tonight, and hopefully you'll see some of the "sniping" games I've been mentioning briefly. In any case, you should meet some of the twinks that are actively queuing regardless.