Yes, I have friends with chronic physical health conditions that know only too well that stress has a significant physical impact. They are pro-active about protecting their mental health, because if they don't then they become very physically unwell.
I don't go for the 'too much stress causes cancer' unsubstantiated claims. It isn't as straightforward as that.
But I think there is plenty of evidence that mental and physical health are inter-connected, and that stress (especially factors out of your control) does have a negative impact on physical health.
And insidious, faux-naive accusations are incredibly difficult, because ANY response ends up playing the accusers game. Nasty and manipulative stuff, because no-one can give an honest rebuttal, and facts are irrelevant.