I doubt not getting a title would produce a significant enough stress reaction to show physical health ramifications. Anger or annoyance, sure, but significant stress?Yes I have noticed since HM's funeral he is looking quite gaunt. I wondered if it was the stress of not becoming Duke of Edinburgh. I notice Sophie looks happy enough so I've concluded he must be ok health wise but it is a bit odd. He's never been this thin before.
Given he's lost his mother, there's significant family stressors around Andrew's bs, the Harry situation, and likely additional responsibilities because of the changes of late, I'd expect if he's lost weight due to stress those are more likely players.