Every major power has polluted near Earth space as a show of power.
[0] https://planet4589.org/space/con/star/planes.html
(On general principles, you could argue you'd need 1:1 launch vehicle parity (number, not payload) to defeat a satellite constellation this way. For each satellite launch, you'd need one corresponding anti-satellite launch into that same, newly-defined orbit).
Starlink satellites are pretty low and experience a lot of drag, with square-cube law working against you. Your shrapnel's orbit will likely decay pretty rapidly.
Relevant, Chinese domestic media reporting on China's own perspective:
https://www.scmp.com/news/china/science/article/3178939/chin... ("China military must be able to destroy Elon Musk’s Starlink satellites if they threaten national security: scientists" (2022))
> "Researchers call for development of anti-satellite capabilities including ability to track, monitor and disable each craft / The Starlink platform with its thousands of satellites is believed to be indestructible"
"Easy to bring down" vs. "believed to be indestructible"—some tension there!
And I doubt China would want to make LEO impossible to move through anyway. It’d affect China badly as well
Also, fairly easy to find from the air.