Generally, speaking the answer is yes.
There was a very in depth benchmarks of many different graphic cards and CPUs in multiplayer Battlefield 4 which was published around 2 month ago. It did show that overall BF4 (and presumably FrostBite 3 in general) performed a bit better in Win 8 vs Win 7. The difference was not mind boggling, but I believe on average it was 6% or 7%.
Below is a link to a review that compares BF4 in Win 7 vs Win 8, but this is not the review I was looking at back in November. Unfortunately, I cannot find that particular review.
http://www.hardocp.com/article/2013/11/24/battlefield_4...