Are the Pokémon Sword and Shield expansion version exclusive?

Solution 1:

The official Pokémon website states that you have to purchase the version that matches you game version so you have to buy one for sword and one for shield. You get both expansions in the pass.

This Nintendo support answer says all DLC are available to profiles on the same console but the question was about Zelda. Howerver, having tried it myself I can confirm the expansion pass is available for all the profiles on the console.

Solution 2:

To the first part, yes, according to https://ec.nintendo.com/AU/en/bundles/70070000009664 you need to buy the shield and sword expansion passes separately and are only usable with their respective versions.

As far as owning for example pokemon sword expansion, and your friend also using sword, that has not been definiteively answered, however, you can transfer pokemon caught on the expansion islands to games / players who do not own the expansion.

Solution 3:

As for the first part, yes, cause they're technically different games.

The second part, the expansion pack is available to profiles that are on the same console.