If you sell something "from when BTC value was lower" then you are, by definition, selling it for a profit.
The point was they are creating losses. For example If you have btc that was mined to a wallet, there is no trail. If you buy 1 btc on coinbase, transfer that btc out, transfer the older one in, sell it, you have a fake loss while retaining the coin you bought, and not really having a loss. There is no way the irs could show that the coin that was sold, was not the coin that was bought. The statement is there 1 coin for 1 coin.
Again, I don't believe something like this is happening, although I don't see why not to do it, if you were one of the original large holders.