I have to admit that I find that very hard to believe, 1.5 MM perhaps, but cm??
I have had my first bracelet for almost a year, full of beads, and I just measured it, and the measurement is still spot on. Maybe they are thinking of cheaper bracelets? Next time I am in the Pandora shop - not just a jeweller that sells Pandora but the actual flagship store, I'm going to ask about this....if they would have to know for sure if this happens or not.
ETA: where is the other forum?