Regarding Openvis 2019: We are taking a year off, so there won't be an event in 2019. The committee is in too much real life transition right now :) We aim to be back in 2020 (probably in Boston again)!
And if you find this all interesting, I discussed Du Bois’s dataviz work and how it shaped discussions on race in the US at @OpenVisConf this year youtube.com/watch?v=RciU_sWY…