Just a description mistake: Bloodletter Maple lists its material type as "Wood, Cypress", instead of Maple. on wood weapons.
The new metals don't seem to be scripted for any effect on making wood weapons. A Rowan iron (normal iron) staff is +1 vs. type, d6 bludge. the 3 metals I tried were +1 vs. type of the wood, d4 bludge... placing all the new metals weaker then normal iron on wooden weapons. None had any elemental damage or other effect.
likewise the bloodletter Maple is +1 vs. type, d4 bludge in iron, and the other metals are +1 vs. type, +2 bludge on the new metals.