Satellites have a shelf-life. You don't worry about upgrading existing ones, so much as build newer, better models.
Lasers aren't all that particularly great either because you lose so much power to the atmosphere, especially firing from groudn to space. If they equipped another satellite with a laser, it would have potential, but again, would be severely restricted in available power. Think about how big the I.S.S. solar panels are for the limited amount of power they generate.
On top of that, we've already tested the technology for kinetic kills in space. I'd say we're quite a few steps ahead.