Amount of currency is decreasing
Wealth relative to the most consistent prices in the market is not changing
The volatile side of the market will adjust accordingly given enough time
If you look at it in the right way, those with less gil right now may end up losing less wealth directly following the version change, as they will be less likely to be able to afford the prices that exist in the volatile areas of the market before those prices adjust for the re-valuation that is occuring.