My thoughts...
Wood making direct contact with the ground will rot over time. Putting a cinderblock on the ground first, will make the wood last much longer. Since you are going to use a deep litter method, I would use maybe even two levels of cinderblocks so that the deep litter composting action is not rotting out the wood walls of the coop. An alternative would be to line the coop wall to the depth of the deep litter with something like plastic or linoleum. In any event, you would want to protect the wood walls from direct contact with the composting deep litter.
Or plan on replacing the wood after a number of years because it will rot if in direct contact with the ground or composting deep litter.
You could use a sacrificial layer, like maybe some plywood, over the inside coop wall and just plan on replacing that plywood in a number of years. If you plan on cleaning out the deep litter maybe once a year, you could inspect the progress on any rot on the sacrificial plywood board to determine if/when it needs to be replaced.
I salvaged a bunch of plywood tops from some pallets, so that is what I would probably use. But you could also use pallet wood planks as a sacrificial layer. It would just take a little more time piecing it together compared to slapping on a big piece of plywood. On the other hand, if you had to replace a rotting board, it might be easier to replace a pallet wood plank piece only where needed.

I have often thought if I had to rebuild a new chicken coop, I might just do a garden shed conversion and leave the dirt floor inside, using the deep litter method. There are many nice examples of building a shed using pallets, so I hope you can find something that works for you. Be sure to post your project here to inspire others!