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.