>that shitposting
Wew laddy. For the most part I don't think they have one (outside of yetsturdy, but it's pretty clear she's balls deep in crazy SJW territory), from the logs most of them just come across as typical 20-something year old liberals.
I don't really find anything notable about that /jp/ mod post as well, the majority of 4chan's users are burgers/europeans and thus likely to be white (including the people that would use /jp/ over futaba/2ch as that indicates they can't into nip and thus aren't Japanese) so the average 4/jp/ meetup in Japan would probably be a lot pastier than your average crowd of nips. Don't think I have it around still, but I used to have a picture of a /jp/ meetup from back in 2008-2009 and everyone there was white as fuck. Would be interesting to see if the /v/ dumper (or /a/ dumper if he's still around) has found anything to indicate shit like that relating to the staff though.
On an unrelated note, didn't warosu used to be populated by a fair number of /jp/ ghostposters a few years back? Where the fuck did they go instead?