http://golfweek.com/2018/02/07/the-forecaddie-pga-tour-takes-stand-with-bunker-liner-rule/
I'm glad, mostly, but without spending too much time looking into this… the bunker liner is man-made, and an obstruction, and the Rules of Golf grant you relief for obstructions for your stance, too. Isn't this a Rule 24 issue?
Again, only two minutes of thought here, but I don't consider a bunker liner an abnormal ground condition.