Originally Posted by flightrisk

I'm sure someone else can explain this better, but the 'hold' is for a specific fare basis. If the price of that fare basis decreases during the hold, you will automatically be charged the lower price. If the price of a different fare basis becomes available that is lower than your held price, you will not receive that lower fare basis/price.

Therefore it is still advisable to recheck fares on held tickets and cancel/repurchase.