We have made significant improvements to the Brush drawing experience in addition to the new Vector Brush Tool introduced in Animate CC 2015 (formerly Flash Pro). There are lots of other new feature additions and key enhancements in this release. Please check out the release notes to learn more about the Animate CC 2015.1 release.
You can update your copy of Flash CC to Animate CC to leverage all the new features using Adobe Creative Cloud desktop application. Please sign-out & sign-in again in case if you don’t see Animate CC in your Creative cloud application.