The World of Warcraft team has posted news about a rather large "hotfix" being applied to the game today in North America and tomorrow in Europe. The hotfix involves the reduction of the Artifact Knowledge cap from 50 to 40.
Developers' Notes: We raised the Knowledge cap from 40 to 50 very late in the 7.2 PTR cycle, out of an abundance of caution: We wanted to ensure that players of all playstyles, as well as alt characters, would view the Concordance of the Legionfall trait as accessible. However, between the additional Artifact Power gains added in 7.2 and others that were hotfixed in after the patch released, we're now well ahead of that mark. Knowledge 40 now seems more than sufficient for players to each Concordance of the Legionfall, and the prospect of months' worth of additional Knowledge still left to research makes some players feel like their efforts in the interim aren't meaningful. Therefore, we're rolling the cap back to 40.
Collecting Artifact Knowledge beyond a few points at Level 40 will become largely meaningless, according to some players, due to the massive amount of grind involved to collect enough to attain a level. According to one player in the comments:
Pretty disappointed with this change to AK. This effectively will make AP worthless after a while, because the gains towards the Concordance ranks will be so abysmally small. The increase of 200 per rank is already tiny as it is, and the prospect of needing hundreds or thousands of tokens to get a single rank is really depressing. What purpose will I have to actually acquire AP anymore if the return on time investment is so exceedingly small?
The Artifact Knowledge cap was raised from 40 to 50 late in Patch 7.2's development as part of a desire to increase overall AP gains. However, after 7.2 launched, we realised it would be better to increase base Artifact Power gains instead of relying on Artifact Knowledge (which takes time for players to research and can make gains earned in the interim not feel as meaningful).
Since 7.2 we have deployed several hotfixes that have increase AP gains in certain areas, one such example is the Elite Strike missions available while the Command Center is active. Now that these changes are live, the acquisition of AP is faster overall, so we felt that 40 is now an appropriate cap for AK and isn't as daunting a prospect to reach.
We also wanted players to have a solid stopping point for AK research, at which point they will have more freedom to focus on their alts.
In addition, the amount of Artifact Power at max level is being reduced from "billions" attained to a maximum of 500k, thereby making the grind to achieve artifact levels in the infinite trait that much longer.
You can check out more of the community's reaction on the World of Warcraft community site.