Teens and 20-somethings liked the fact that Snapchat was their smaller circle of real friends. Facebook has that goofy uncle, and coworkers from 5 jobs ago, and old classmates you don't really want to stay in touch with. Facebook has too many "weak ties".
Therefore, Facebook could clone every feature of Snapchat but it can't change the fact that it is still Facebook. The new features might keep Facebook users from switching to Snapchat but would it entice Snapchat users to switch to Facebook? Sure, people can use social networks for a myriad of reasons but Snapchat the network seems to be a dominant factor.