Hm, when it comes to "intentional themes", my stuff has always been related to duality (peace-chaos, fate-choice, truth-lies, life-death, you name it) and there having a "middle path" in said duality, to show not everything has to be about picking only one side.
Now when it comes to accidental themes, some people I've explained my story and characters to, said that there was an overarching theme of all characters having an issue in their lives (parental abandonment, losing someone important, being outcasts, etc) and having a choice: close themselves off to the real world and live in a world of fantasy to avoid all pain, or leave that fantasy behind and face said problems head-on; results varying for each character.
And also realized a general theme of "curiosity leading to a major change"; the full phrase goes "curiosity killed the cat, but satisfaction brought it back", after all a character finding something off about the world they live in thanks to curiosity, is what may lead the status quo to turn on its head eventually, for good or for bad.
That's what's explored in my comic "Heroes of Paradise" -- the main characters got into another world by accident, and are completely blind to the underlying conflict they're getting themselves into (which is, two entities trying to have a final say on the reawakening of all magic; one wants it to remain asleep to keep the Worlds safe, the other wants to hasten its awakening to bring chaos)
And the MCs being found out could be a turning point to the conflict, either to maintain the status quo or break it completely, if you know what I mean