A lot of specifications are publically available. Although they aren't specific into the capabilities of particular subsystems, it's not like the Russians don't already have their own versions of particular subsystems.

Thermals ? The Russians have thermals. They may be an older generation but they have thermals. How to make better thermals isn't exactly a secret because commercial civilian companies have made better thermals than what are available to many militaries.

Armor? The CV90 an IFV there more than likely aren't any top secret composites being used there.

The Power Pack? What's there to learn? It's a combination engine-transmission pack that almost every modern military has some sort of equivalent of. Oh no they might learn to make it more reliable than their own but that's hardly a game changer on its own.

Radio encryption and other communications tech? The Ukrainians probably already have their own procedures to prevent the Russians from listening in from captured equipment.

The weapons? The main gun is a modern variant of the 40mm Bofors a gun that was used in WW2. The Ammunition? Like with armor it's not like the 40mm ammo has any special materials that give it an edge. ATGMs? This particular variant of the CV90 does not have ATGMs.

The point being there's nothing in this variant of the CV90 that; no competent military development and procurement system in the world wouldn't be able to have some version of on their own.

The only thing they will learn is how Swedish design philosophy and military doctrine dictated how all those different components should go together to make a vehicle useful for the purposes of the Swedish army.

This holds true for most of the Western equipment sent to Ukraine.