Yeah, finally I prefered to “listen” to what my quest tracker in the game was telling rather than to the guides. I discovered, horrified, though that for the completion of Insurrection I needed the completion of 10 world quests in Suramar, and I don’t see world quests on the map, so that I am really forced to do the Uniting the Isles reputation quest where I must achieve friendly reputation in four other faction than in The Nightfallen. I though and remembered that some 7.x.y patch removed the reputation requirement for the whole Insurrection questline, but apparently, either I am doing something wrong or I was wrong … The more I complete stuff toward Nightborne Allied Race, the further away the completion goes … 
EDIT : this last problem led to a new bug report :