Earlier quoted context omitted.
I don't believe this is true. And of course detonating nukes in space would be an act of war against the whole world.
nukes optimized for EMP may be able to do this just fine. https://en.wikipedia.org/wiki/Nuclear_electromagnetic_pulse
That very article says "The damaging effects on orbiting satellites are usually due to factors other than EMP". Also "for equipment to be affected, the weapon needs to be above the visual horizon". Given how low Starlink orbits and the fact that they are dispersed evenly over the whole Earth, the number of weapons you would need to detonate just to ensure line of sight to every satellite at a range short enough to be effective is absolutely enormous.