It seems to me that different surgeries have different ideas about "reviews". A few years ago, my surgery started doing reviews like the one the OP describes. Blood was taken during the review, so the results couldn't possibly be discussed at the time. Follow-up consisted of a brief telephone call with a GP, who usually didn't do anything.
However, everything has now changed and I can't believe my luck. I believe I now have what I would call "gold standard" treatment. I receive a reminder every 6 or 12 months to book a blood test and a review. So I have a blood test and take along a urine sample. A couple of weeks later I have a face-to-face review with a diabetic nurse, who is an absolute star - she really knows her stuff. I wasn't surprised to discover that she has an MSc in diabetes management and is on the board of a national diabetes organisation and publishes peer-reviewed articles. She's campaigning for better diabetes care, so I guess she uses the care she offers as a "model".
I haven't seen a GP about diabetes for years. The advantage of the care I now have is that I get longer appointments with the nurse than I would with a GP (nurses are cheaper) and I can discuss all sorts of related problems. For example, I have a history of depression and insomnia (which have an effect on diabetes), so she always asks me about my mood and takes action if needed. I also have problems with a hip (which affect how much exercise I can do), so she arranged X rays and physio. She couldn't prescribe painkillers, so made me an appointment with a GP, who did prescribe them. In other words, I feel as though my diabetes is treated holistically.
I suspect part of the problem is that some GPs don't have a specialist diabetes nurse, to whom they can delegate, so have to organise things differently.
My only fear is that she's so good that she'll be snapped up for promotion somewhere, so I always give her rave feedback.