> Presumably they're planning on doing in-orbit propellant transfer to reboost the satellites so that they don't have to let their GPUs crash into the ocean

Hell, you're going to lose some fraction of chips to entropy every year. What if you could process those into reaction mass?

Another significant factor is that radiation makes things worse.

Ionizing radiation disrupts the crystalline structure of the semiconductor and makes performance worse over time.

High energy protons randomly flip bits, can cause latchup, single event gate rupture, destroy hardware immediately, etc.

And just like that you've added another not never done before, and definitely not at scale problem to the mix.

These are all things which add weight, complexity and cost.

Propellant transfer to an orbital Starship hasn't even been done yet and that's completely vital to it's intended missions.

Or maybe they want to just use them hard and deorbit them after three yesrs?

"Planning" is a strong word..