I think that is a good conjecture, Zim. I don't know if it is true...that is where the research would be required to vet the cases.
Regarding this overall issue, here are some things that came, immediately, to my mind:
(1) Healthy people breath almost exclusively through their nose. Your nose is there to filter; if you didn't need a filter you wouldn't have one.
(2) Viruses (and bacteria), in relatively small numbers, are generally harmless. They need to get concentrated into hundreds of millions, if not billions, before they stand any chance against a healthy immune system. That is, they need a BREEDING SPOT, within the host, where they are relatively protected from the host's immune system, for a time.
(3) The nose is a preferential breeding spot because
(a) lower temperature (which invaders prefer; that is why you get a fever, BTW: to kill the organisms)
(b) reduced/restricted blood flow, so the hosts full immune system doesn't have full access.
I could probably come up with some other good reasons. My point is that the lungs and the throat, and the inside of the mounth, do not have these advantages for a respiratory virus or bacteria.
That said, pneumonia may well begin directly in the lungs, I don't know. If so, that would probably be an example of your hypothesis being borne out.
But pneumonia - whether viral or bacterial - is not a cold. So I am back to my original hypothesis.
Now, what does it matter? Think about all the sick time humans go through, due to respiratory viruses, in particular, and the insane cost society bears for sick time.
And then imagine that all it took to possibly get rid of 99% of all colds, and possibly flues, was just a slight upgrade in BASIC, INEXPENSIVE, hygiene?
What would we say these days about people who didn't wash with soap and water after pooping. Who didn't disinfect wounds, nor hospitals, before "medical care"? Etc.
And what excuse do the ersatz “scientists” who work at the CDC, FDA, etc. have for not having the slightest conception -- nor curiosity in -- the basics of how diseases get started and spread.