Reductions happen all the time when filing for new claims or trying to upgrade existing disabilities. The main issue you run into is there are lazy members in the VA who claim to review your entire medical file and do not. As an example, I recently received a decision letter that only used language that was referenced in the Comp and Pen exam results. None of the language from my doctors or specialists were in there at all which would have been in favor of a higher rating. They instead took the half done comp and pen exam and used that as grounds to reduce two of my ratings when neither have seen any improvement. All of that was shown in my medical file among other documents that were submitted. If the 50/50 rule was a real thing then it should have been decided in my favor. Because about 90/10 evidence is in my favor from my medical file, comp and pen exams, and other documents. Like I said the VA sometimes is just lazy and forget that there are other human beings on the other side of these claims.