After the latest patch of Guild Wars 2, players found the drop rate of legendary precursors reduced. And they doubt if ArenaNet made changes on this. There’s an official response posted on the website:
We’ve seen players discussing the topic of crafting legendary precursor weapons and claiming that we’ve made changes to make this more difficult. We’d like to be clear that we did not make any across the board changes to reduce the drop rate, nor was it our intention to significantly increase the difficulty in acquiring these precursor weapons.
We did fix a few bugged recipes that were rewarding Legendary precursors more often than they should have been. These recipes were mostly using Rares in the level 70-75 range and mostly affected the precursors for the greatswords and the dagger. This has had some effect on the drop rate when using lower level rares to attempt to get a precursor but it was never intended for that to be the best way of acquiring these weapons. The recipes for throwing in level 80 exotics have not changed at all.
We have been watching the prices climbing on Legendary precursors and share your concerns about some of them becoming too expensive. We will continue to monitor the situation and will make any adjustments we feel are necessary.