They'll get smaller. They may change during the process as the muscle grows and takes up space, but once the fat is gone that will leave a muscle.
Calves are funny though. I've heard that a lot of women who have been obese have very large calf and leg muscles just from moving ourselves around. I know I do/did. I can out do a lot of men with the leg press! I thought my calves were hopeless. They have definitely taken shape nicely here just recently. I have never and probably will never have slender calves that will fit into high boots, but I'll take what I have now. Oddly, I'm most happy with my knees. LOL!
There's a lot of debate as to the best method for lifting whether high reps low weight or low weight reps high weight. I prefer to mix it up. If I'm going with lighter weights I lift 20 reps to the point of fatigue by the third set. If I'm lifting heavy I lift 8-12 reps to the point of fatigue by the third set. If I can't get out the last rep, I know I worked it.
For legs I love squats, lunges and running up and down stairs. For the calves I particularly love a movement that involves the bicep. Using light weights, (5, 8, 10, 12...I'm up to 15), stand in place holding the weights in preparation for a bicep curl. Raise up on the toes, then raise and lower a bicep curl, finally lower the heels back to the starting position. The extra hold at the top of the calf raise along with the coordination necessary for staying balanced while swinging the weight to a bicep curl works the calf really well.