This paragraph best represents my fear about this act going back into full force:

Revising the law has long been a priority for Republican lawmakers and industry groups representing oil and gas companies, logging interests and construction companies. To them, NEPA embodies delay, cost overruns and court battles. They have accused environmentalists of weaponizing the act to defeat projects they oppose.

In short, I fear this will give more ammunition to those opposed to the mine, and give them further opportunities for lawsuits and delays... even if their arguements are completely unfounded.