I don't expect campaigns/adventures to be exactly the same as movies or novels. But does anyone design their scenarios or campaigns around a particular theme?
Sort of.
I'll take my Ashen Stars game as an example - in that game, each character has a Drive, a personal goal or reason to be out doing things. Any time I built a scenario to address one or more of those Drives, I'd have a de-facto theme.
As an example, one PC was of a race that wasn't fully sentient before a corporation did some genetic work on them. From the company's perspective, they were... an intelligence/spy asset to be leased out. The lease was held by another PC, who pointedly ignored the terms of the lease and let the asset-PC do whatever they wanted.
But, the PC still had a goal to not be an owned thing, to be fully seen as a person. So, any time I'd lean into that, I'd have themes of self-determination and autonomy and what "freedom" really means.