To me, really, the novel spent a great deal of time pointing out the fickleness of the UK Government, the idea that it was prone to fads, and that people simply went along with it. Only a handful swim against the tide. Even Alex's parents are reprogrammed more or less at will by the media. Burgess has touched this material before in
The Wanting Seed, with what was acceptable lashes back and forth.
That came through sufficiently in the movie that I feel like this delivery was fine.
Similarly, the free will issue came through fine. Alex lacks the capacity to dwell on the subject. It falls to a prison chaplain to even ask. Nobody cares, of course, this is about results, not reformation. If Alex and other recipients of the Technique must stagger through society wearing invisible chains, that's fine as far as Government is concerned. Again, well-conveyed.
These two themes collide at the end, wherein the Government changes its mind and finds it politically expedient to restore (or just re-re-program) him to his original and savage state. ("I was cured alright.") Twenty-one, incidentally, is the terminal age in the novel for Logan's Run; youth violence and an age divide was certainly on the minds of some.
I felt like Alex himself was almost, well, not irrelevant, but simply a ball upon which multiple dogs had set their sights.