I would guess so. There is always a little muscle loss just cos its not moving the extra weight around it sorta atrophies.
I also guess an average weight loss of 1/2-1lb a day depending on your weight is nearly the long term maximum you can hope to attain. More than that is muscle. Muscle is more water and less calories per gm, so to get 3600 calories, you need to burn 1lb of fat - which has nearly no water or you have to burn ~10lb muscle which has 70-75% water and only produces 4 calories a gm when burnt. 1 lb muscle therefore only delivers ~350 or so calories.