I admit I haven't been keeping up with the latest developments but from what I've read during the past month or so, this shouldn't be the case. The fork is a change in the protocol that allows for bigger blocks than the current 1 MB limit. I don't believe that the total number of coins is planned to change. Perhaps you are confusing the concept of larger blocks (measured in megabytes) with larger block rewards (which won't be affected by the fork):
The discussion recently in the Bitcoin ecosphere has been to increase the block size to 20MB, thereby allowing more transactions in each block, increasing the transactions per second...
...With Bitcoin-Xt, the plan is to go ahead with a big increase at first that will be followed by automatic incremental block size increases over time.
Link: http://www.cryptocoinsnews.com/bitcoin-xt-pushing-ahead-bigger-blocks/