How to move a subvolume to a new drive in btrfs?
Your last step is unclear to me. I think you have moved your data from btrfs array A to B.
You used to mount the directory with
UUID=0888211b-2636-4eb5-97da-52679d93a275 /srv btrfs subvol=/@/srv 0 0
So you should replace this line in /etc/fstab with
uuid=273dbdbd-16d9-4ae4-bde7-d30a48474a44 /srv btrfs subvol=/@srv 0 0
You need to change the UUID and then reference the subvolume.
The replace command is used to remove disks from an array. I don't really understand what you are trying to do.