I have had the same worries about the line-up. I have been a regular attendant at Roskilde since '08 and there is no doubt that Roskilde is MY festival because of the broad array of world music. To me, that is how they distinguish themselves from the other Danish (and nothern European) festivals - and the most important genre for their bordercrossing image. Often, it is amongst the world music that I have had the best concerts; both for parties and for heart-touching moments. And they always appear to make people with otherwise widely different musical preferences come together. OK, introduction over!
I was also worried that Roskilde was slowly abandoning this genre. Normally, it would be around 10-15% of the total line-up. However, as I looked trough the program so far, I also think we can add bands like 47Soul, Black String, Den Sorte Skole (who are mainly sampling obscure world music nowadays - and do it well!), and Afenginn to your list. If we expand the world music 'box' to include bluegrass and country (no need to have the euro/americanocentric arrogance towards regional genres, right) we can also add Pert Near Sandstone and Margo Price.
That adds up to about 10 band, and a little more than 10% of the line-up so far. But I do agree that we need more 'pure' world music acts playing some sweet afrobeat, cumbia or whatever. I don't know whether it's a contemporary thing that we don't see them yet. Remember that we used to have several awesome balkanbrassbands in the lineups every year, but that stopped around 2010 which I guess was reflecting a trend.
So, this is my first post. I have been a ghost in here since about 2010, but this post by Wallu forced me to finally create a profile and join the discussion