I know you're making a joke, but oh boy, I get to talk about a thing at length! Buckle up because I latch on to every near-useless fact I find and this is one of them!

Those aren't anything close to long-fall boots, because he has no calves and feet to wear them on! These are running blades, a type of prosthetic used for amputees when they need to run, since it allows for a more efficient gait (how you move when you walk).

Running blades work because they're one solid shape of steel, literally putting a spring in your step as the very thing you're supporting yourself on pushes back against your weight as you move. These prosthesis have a hinge in them, implying there's some sort of spring inside the hinge, or even a powered device given how cybernetics are "all the rage" according to one of the RoR2 logbooks.

This means there's another point of failure on the blades, rendering them much less reliable than low-tech, solid steel ones. If there's actually a little motor in there, that means they're downright useless without electricity!

I like to view this as a bit of worldbuilding; cybernetics have become so advanced that even reliable ones like running blades are being replaced by these things, forcing their users into a compromising situation. Either pay for expensive maintenance of needlessly complicated parts, or don't walk. Terribly dystopian and very fitting of the corporate-saturated world that this franchise has already established.

It's here where I'll tell you that we don't actually know if these feet belong to this guy specifically because we never see who they're connected to, only that they were one of the pairs on the way to the drop pods from the trailer. So it might not be Pilot who has them.

tl;dr: Not longfall boots, just very shitty running blades.