They will work even better. They have not had a quick bacterial breakdown; they are undergoing slow fungal decomposition. Bacteria may sit at the base of the soil food chain and provide nourishment to everything above them, but they have their limitations. Fungi are far more important to building soil structure and they are capable to moving nutrients around in the soil and sharing them with plant roots that they colonize; something that bacteria don't.
If you see any mushrooms among the leaves on the forest floor, these are diamonds in the rough that you need to incorporate in your hugelbeds. Crumble them up and sprinkle them widely so that their spores have the maximum opportunity to propagate.
You don't need compost or manure, although if you have them they are nice additions. You can use the top soil alone. I would save the leaves and straw for mulch.
Not so fast naughty spawn! I want you to know about
the permaculture bootcamp in winter (plus half-assed holidays)