Legion Developer Q&A - PvP gave us lots of information about what they want PvP to look like come Legion and the message was heard loud and clear: WE WANT HIGHER RATED PARTICIPATION.
Do you think that will happen and why?
Most players play WoW a limited number of hours per day/week and enjoy all parts of the game at various degrees of intensity. Setting yourself a target (gear wise) was always part of WoW and its a cool thing. Legion will weaken PvP awarded gear as compared to WoD for PvE. Seeing how WoW is a fantasy RP PvE game, PvE gear on the other hand will still reign supreme in both areas of the game. (Talking for the majority of the player base or casuals)
While the intent is to force more Rated Game play via extra rewards and faster gearing, at the end of the day the casual player will figure out its far easier and less stressful and probably cheaper (yes paying gold for boosting is a real thing) to buy raid boosts (even Mythic tier).
Raid guilds will quickly discover a huge spike in demand from casuals and I fear the 'higher participation' in rated will be just for that 'first win' and end up being cannon fodder for the actual teams who play rated ..
In other words another expansion of Acti-Blizz dictating to please the minority hardcore while totally shafting the casual player ..