Yes, they can be made to work for space combat, but none of the strengths of a BSP engine apply to that environment. Its not even worth generating a BSP tree, because the optimum tree is one huge leaf covering the entire play area. (Unless asteroids count as static terrain, but they are generally hideous shapes to carve with, when something like that turns up in an FPS level its normally explicitly subtracted from the world so that it doesn't effect the tree).
In short, its the wrong tool for the job. If its all you have, you can make it work. If you have the choice, you would find a better tool. And surely EA have a choice here. Which makes me suspect that, given the studio they chose and the tools used by that studio, they aren't making a classic wing commander game. Normally, Id be unhappy with that conclusion, but EA control a number of franchises, and there are many I would like to see brought back.
