I"m very wait and see on this topic, cause it is possible they may be more adventurous with gear in the upcoming expansion.

When you think about what they have set out to do, they are making a normal mode, and hard mode for the raid which in a way allows them to release gear that may effect abilities but these pieces of gear would mainly be used to gain an edge in hard mode content while making normal mode that much easier.

Basically what I"m getting at is with the current gear design that system would work fine with normal mode raids but for the hard mode raids you might need that piece of gear that enhances certain abilities or traits for your job to make the experience easier or to get through certain aspects of the content quicker or more efficiently.

Time will tell though but I do think that if they do wish to add another depth of strategy for the "hardcore" then adding gear that effects abilities is a good way to go while also increasing the challenge of said content.