Just to be clear, you can still make Soft Hammers from Wood. But the missing NEI recipe is a bit confusing.
NEI only shows the rubber hammer head recipe when viewing how to make the generic ‘Soft Hammer’ item.
Vice-versa, looking for uses of any ‘Wood Hammer Head’ item does not show the Soft Hammer as product.
Affected versions: 6.14.03 (probably introduced in 6.14.02, can’t test that one)