There were a lot of baby Kylos last year. The name jumped the popularity ranks from #3269 in 2015 to #901 in 2016, according to the U.S. Social Security Administration. So it’s not incredibly popular (to contrast, Ben was #704, and Benjamin is #6) but it is getting more popular. And note – it’s still less popular than Anakin, which is #778, up from #910.
At #175 Finn is the most popular sequel-trilogy related name associated with a major character – but it’s in been in wide use and gaining in popularity for more than a decade now, so we can’t peg that to Star Wars alone. Rey hasn’t shown any major growth, though it did jump from 904 to 868 (though as a male name – it’s not in the top 1000 for girls.)
As for the old standbys, Leia is #321, while Luke is #29. Poe, Han, Padme and Armitage (I had to look it up just for kicks) are all unranked.