Yes. The king could have received it via compassionate use (or maybe he didn't receive DCVax-L at all). Perhaps also, and this is speculation, his successful treatment pushed to influence the NHS to make this available to others. I am not saying this happened or is or is not probable... merely that it is possible.
I feel that in answering a direct question of 'possibility', I am perceived as if I am advocating it. I am not and don't care if it did or did not occur.
Given all this, I can’t definitively say King Charles influenced NHS’s decision to place DCVax-L on the HCD list, nor can I assess the probability of it. But I can say, with confidence, that it remains a possibility—one rooted in reasonable speculation rather than baseless conjecture.