There are international agreements for central banks to dump gold, and the Swiss were part of that. But yes, partly because they can't afford to let their currency get too overvalued WRT the euro. There's a huge amount of day-to-day trade into Germany and France and it would kill Swiss manufacturers and merchants to let the Franc get too high.
Thanks Palmer. Your economics posts are always enlightening. I am aware of all that Central Bank gold dumping. By default they hate gold
There are plenty of rumors of the Russians shooting for a gold backed to rubel.... They will promote it as a reserve currency