In the notes regarding copper ingots, is states

"Copper ingots are not part of any new blacksmithing and armoring recipes, rendering the item obsolete. To ensure that existing materials are not wasted on a no-longer necessary item, potentially affecting the in-game economy in an adverse manner, we have decided to remove the two recipes for copper ingots altogether."

Ok... but then further down in the patch notes, in the "New Recipes" section it says the following NEW recipes will require copper ingots:
Floating Minnow
Copper Barbut
Chocobo Fly
Copper Rings
Copper Scepter
Copper Needle
Bronze Ornamental Hammer
Hempen Doublet Vest
Hempen Kecks

Also, Goldsmithing has an updated recipe for Copper ingots, and vendors will still be selling copper ingots. Copper ingots will remain in the game and will indeed be necessary for those synths.

It seems that what they meant to say in the notes was that the copper ingot recipe was removed from armorer and blacksmithing, and will now be exclusive to goldsmithing.