Correct, there isn't much load - about the same as any other vehicle. But lead-acid batteries like to be kept topped up, discharging them unnecessarily isn't good so given Tesla have the ability to charge it up periodically you would expect them to do so - not wait until the battery is deep-discharged.
The 12v battery has been a bit of a weak spot in the past, so-much-so that they have moved to the lithium ion one in the latest shipping vehicles. Not keeping them topped up is likely to just make the situation worse.
I definitely support Tesla moving away from waking up every 24 hours, but I assumed they would move to every 60 hours, not potentially 7 days or more.