In short yes, but not as you may remember / recognise. We are all now employed on New Employment Model (NEM) Ts&Cs under which I think the majority serve for at least 12 years. I think there are some areas (probably specialist, I’m sure someone can confirm) that serve for shorter periods of 6 years. At the same time the 16/38 pension point has been replaced by a 20/40 point where you get an Early Departure Payment. If you leave at your 12 year point i.e. before hitting the 20/40 EDP mark you still get a resettlement grant and I suspect a preserved pension at state pension age.
The cynic in me thinks there is a concerted effort to change the demographics of the Forces such that most people start their working lives in the Forces and quickly move on. Yes it keeps things young and fresh, but it also reduces your pay and pension liabilities significantly over time by folk leaving whilst still junior and befor hitting a pension point.