Don't know all the history but I did a little bit of digging.
The Prone thing seems to have come about when an RGB asked for Prone to be removed from FT (reading between the lines, I don't think they wanted the extra work of having to clear shooting lanes so that a prone shot could be taken).
That got quashed, but instead a clearer definition of Free Position and Prone was written.
The Windicator thing started when Portugal asked for clarification on the use of powder puffers (I think in NZ one shooter was upset that his gun got covered in Talc).
From that request the Windicator definition came in.
I did ask Andy Kay's about this and he said that these are not rule changes, merely clarification on the existing rules. Since this new definition also includes an additional Penalty clause that wasn't there previously, this is quite clearly a rule change rather than a clarification.
Also, it would mean that if these were always the rules, there has been an awful lot of rule breaking going on unchecked for the last 3 years.
After having read the Constitution in fine detail, there isn't actually a process for changing any of rules. So technically, even if there was a unanimous vote of all the RGB's then you still couldn't change the rules, because the constitution doesn't allow for rule changes.