I just joined the Fast ring on my Lumia 950 XL and installed build 14965 and I got two notifications about Gestures Beta when the phone started up. I was upgrading from the latest Production build. There was a place-holder for the icon in the popup and there was no notification in Action Centre afterwards. The first one said something about trying out Gestures Beta and the second suggested providing feedback for it. I used to use the old Gestures Beta on my Lumia 925 but I've never had it installed on this phone and haven't restored a backup for a long time. I'm hoping that this was a mistake but that they are working on a new version of the app for Windows 10 Mobile. Mind you, I'd expect those gestures to be baked into the OS rather than released as an app, so I'm a little confused.