The Creation Catalyst appears to be receiving some new updates in The War Within, as our datamining indicates that it will now allow players to catalyze weapons in addition to pieces of armor, converting them into new weapons with predetermined stats.
Referred to in game as the Matrix Catalyst, the ability to affect weapons appears to be a new function the same tier-set converting Revival Catalyst of Dragonflight, previously known as the Creation Catalyst in Shadowlands, as we previously datamined a The War Within version, located in the Earthen capital city of Dornogal and serviced by the same Custodian Khubon.
This suggests that it is not a new system of power, but instead allowing players to catalyze weapons in a similar manner as non-set pieces; converting them to similarly named (but not bonus enabling) pieces of gear with predefined stats. This gives players an option to improve unfortunately itemized weapon drops, though because these «extra» pieces do not enable set bonuses, it remains a secondary and likely minor point of customization.