That is a good theory "If" one wanted to worry about it. But i refer back to the "there is no explanation it is what it is, budgets and tv" thing..BUT i have a new analogy i thought of. How many actors have played Batman? On the soap "days of our lives" (3 ex wives all watched it, i had no choice but i won't apologise for thinking Hope is HOT), They Constantly changed actresses for certain lead characters or males to, they offered No explanation, because as a fan or audience, you have to overlook that as "the character" how about this- Robin curtis or Kirstie alley saavik? There will NEVER be an explanation for her change of appearence, its a NON issue because in terms of "her character" nothing changed from the POV of the characters around her- We as an audience have to deal with it as Drama behind the scenes and Hug the "Character" and not cry over the actress who portrays her. This is no different- everyone really needs to stop trying to create explanations- ENT canon explained it, Retro virus blah blah- Time to Move on.
But Your theory is in line with explaining the KOR, Kang, etc non ridges to ridges, Or as Phlox said "in time this can be reversed" so a cure was found after TOS and kang, Kor and whoever got Treated and are Ridgey again--yay!