The car will recharge the battery with a specific current that it can handle, as the battery ages it cannot be recharged with the same current so the computer will lower the recharge current no to harm the battery thats why it is okay if you disconnect the old battery to work on the car and reconnect (the same battery) in this case you don’t need to reprogram anything.

if you are replacing an old with a new battery you have to reprogram it to tell the computer that this is a new battery and you can charge it with the current a new battery needs(supposing its an OEM battery or a battery with the same AMPs and CCA as the original one)

If you are afraid of getting stuck on a radio code not having it or so you can keep the car running, disconnect the battery and place the new battery right away before the car shuts off, probably you won’t get any codes and if the alternator works fine and the battery is disconnected for few seconds it wont shut off.