Yo! 19s are very much active! If you want to premade with/against other twinks then mankrik is in fact the strongest option, but other servers still have twinks, even if they are dwarfed in size by Mankrik's population. The point I'm trying to get to is that if you want to premade, make a twink on mankrik, but if you already have a twink on a different server, that option is still fine : )
On top of the previous post, I can just add, that you can practically gear a 19 twink in 1 day if you have a decent AH (apart from LFH and AGM ofc). So the time invested in actually making it, isn't too bad.