The FCC submitted a total of 20 submissions to the ITU, each requesting permission for 1500 satellites in various Low Earth Orbits. The company wants to place them in lanes between 204 and 360 miles in height, which MIT's Technology Review notes may be a concern. Aerospace Corporation's Roger Thompson told the publication that although that area of space is purest, it is also where we tend to fly spaceships, including the ISS. He said flooding the area with thousands of satellites "will have an impact on future human spaceflight."
That said, asking for permission for 30,000 satellites does not mean that the Starlink project will actually launch a total of 42,000. Some of the company's critics believe that submissions are just a tip for drowning ITU in studies now that it is on the verge of changing its rules. Whether true or not, filing at ITU is just the first step in a very long process. SpaceX has seven years to launch a satellite with the frequencies it requested, and it will have to operate it for 90 days before losing access to spectrum rights.
The company launched the first 60 Starlink satellites in orbit earlier this year, with plans to launch 60 more this month and even more in November.