It doesn't meet a perfect theoretical definition of net neutrality, but it's a set of defined legal limits on the extent to which providers can treat different kinds of traffic differently.
Ok but the main limit people care about is music and video streaming being treated differently
Net neutrality is not theoretical, it is literally the default setting.
Any deviation from that default requires special effort be taken to identify network traffic and treat it differently, and as soon as you have made that effort you cannot truthfully claim to have net neutrality. The UK does not prohibit net neutrality but it does not require it either (according to the comment I replied to which I have not verified).