Mm, true. Manifest publicly that hero may have been a better wording.
I did not mean that he kept the hero repressed. But he did hide it from view by acting as covertly as he could.
And Jonathan WAS worried about Clark. Still, maybe more about how he would deal with the burden than just about his physical well-being, even if he had no sure way to know how impervious he was in that aspect. But he knew that emotionally Clark was as vulnerable as any, and maybe more than many, being a sensitive individual from all hints. So the emphasis from Jonathan may be more on protecting him through keeping all that covert as much as possible. But the way people saw it was just about hiding. The abstract larger sense you mention kinda got lost for many.
Superman could have actually come out in the open and never revealed his alien origin. Or waited until the world was ready. Or when Zod showed up and it came out anyway. In the comics it was not an immediate thing. Perry White originally made it known to the public. In the Donner movie Superman lets Lois make it public, with a rather funny lack of logical response. I feel MOS handled that in much more logical fashion.
The concerns of Diana's mother were different, but I don't think we should be reductive of them, either, and they may be developed into greater depth. I do not know that yet.
That is why adaptations from the Donner movie until now has kept Clark from manifesting his powers openly until after his adolescence. I never followed Smallville so I cannot say how that well the slow progression there worked out.
But the aspect of Diana being sheltered all her early life while Clark was not remains very interesting. It allows for Diana to experience drastic culture shock in her coming out to the world, as a challenge to her outright idealistic crusading nature, while Clark had been facing the uncertainty of the world ever from the start, in environs where he had more trouble fitting in while growing up. Diana may have also felt isolated by being the only child amidst immortals, but the whole culture appears to have been supportive of her, unlike Clark who only had his parents.