I think you have your distances wrong. Geosynchronous orbit is 36,000km not miles.
LEO is a range between 300km - 2000km. I suspect the satellites will be on the higher range to reduce atmospheric drag. The IIS has a 400km (250 miles) orbit and it's orbit decays at 2km/month without correction maneuvers.
That's the crazy part, he didn't have his distances wrong. Part of the constellation is planned for an orbit of 340 km which is ~211 miles so close enough. The satellites are only intended to have an operational lifespan of 5 to 7 years. That's not a typo, that also means that given the massive size of the constellation that SpaceX will need to average one launch a month for StarLink with 105 satellites on it. If one of the lower orbit satellites goes dead, without actively maintaining the orbit it'll decay fast enough that it'll passively deorbit itself without risk of it just becoming a derelict satellite for centuries.