This has been in the car since the beginning... It also shows up on loaners...
It used to be that you could NOT remove these "charged" locations... However, a few years later, they made it so that you could delete previously charged locations...
Play with settings if you don't want to store.
It's useful, because i dial down my 48 amp charging on our S as I run it at 44 amps so that BOTH chargers are used at 22amps each (dual charging Model S)