Seems to me that the DoD made this decision because the lawsuits filed by some pretty impressive military females would have been tough to beat because of the evidence that would be presented. There have been many female casualties in Iraq and Afghanistan.
I think this mostly affects the females that really want combat assignments based on their own abilities and to advance their careers. Combat experience and performance are major factors when determining certain promotions.
I doubt that that the US military would ever give a combat assignment to any female that does not volunteer for it.
There is no draft right now and if Congress or the President ever reinstated the draft, there is no reason they could decide not to draft females, or to not put females in combat assignments unless they volunteer.
Lifting the restriction does not mean that the US military has become gender blind in how it does things.
Where Ignorance is Bliss, 'Tis Folly to be Wise.