There's been a lot of discussion on here about it, I can't remember what the outcome was but I don't think it will be happening very soon, the police don't have enough officers to govern it all (or the resources) and I'd say that there are bigger things to worry about at the moment like Brexit and more importantly knife crime.
The other problem will be trying to find out who has an air rifle, they are like push bikes, they have never been licenced or properly controlled in the past, so trying to trace them all will be impossible, it's also down to the individual, some of us will be honest enough to get one but many others won't bother and as per usual, it will be the honest law abiding shooter/citizen who will get picked on and the trouble makers will just sink into the shadows.
Pete