Asmongold and others have expressed the opinion that there is no real purpose to seek out farming AP. It is not required. Asmongold is a top tier Mythic raider and even he believes that, and I've heard similar from other high tier Mythic raiders.
Why isn't it a necessity? The gain from every additional rank of Concordance is small. Sure, is 2000 to 4000 a big gap? Yes, but keep in mind Blizzard says they dont expect anyone to make out this artifact the rest of the entire expansion. Let that sink it. They expect NO ONE with maybe a year+ to go in this expansion to max the artifact we currently have. Your time spend grinding NOW gets nullified with every new AK, so just do your normal content cycle. The highest traited people in the world are only 3-4 traits ahead of people playing significantly less than them. (I'm at 47 traits, almost 48 traits for example)
Worldwide, there are only 2 people who have Concordance.
Blizzard doesn't want you blinding your eyes farming Mythic+ 8 hours a day, and this idea that Mythic Raiders have to constantly be farming AP is false, and is going to lead to you burning out
Just doing your natural content cycle will get you enough AP to be good enough. As long as you have Rank 1 Concordance for Tomb you're good to go, with 5 weeks to go and 5+ AK's to go by then, even normal mode raiders should be hitting Concordance. Blizzard wants you to do your scheduled content like Nighthold and other things to passively get AP.
A lot of Mythic Guilds dont even do LFR and dont even do EN/TOV anymore. Don't get in this mindsight "omg when Tomb comes out I have to do LFR for every single one, do normal/heroic for EN/TOV/NH and now Tomb, I have to do every single AP world quest, etc"
No, no you really don't, and that comes from some of the best WoW raiders in the world.