Interesting set of tweets. Not because the Battery Swap Station was unexpected but because Musk sees Supercharging as the future and battery exchange as a stop gap. The philosophy makes some sense when you consider the future batteries will be cheaper and bigger and charge faster, while swap stations, while fast, are huge undertakings and require a lot of logistics to keep charged batteries in stock.
Last year, Tesla CTO JB Straubel told MIT Technology Review that Tesla was intent on cutting charge times in half and in half again. So a 40 minute full charge might just take 10 minutes in a few years.
If you can add 200 miles in a 10 minute stop, a 2 minute battery swap may not be as valuable.
Musk mentioned the commercial aspect of Battery Swap stations which would make sense for professions like taxi services that compile over 300 miles/day as well as long haul semis which won’t want long stops in the middle of their shifts.