Yes, but alien often gets used about as easily as magic
Now you design a starship that could keep functioning for, say, 3
million years (the distance between the Milky Way and Andromeda
galaxies) and you think of a reason why you might want or have to
leave an entire galaxy and try to make it across intergalactic space.
As I said, saying they are alien is just too easy a term to throw
around. Even aliens have to have some kind of logical motive for
their actions, even if it is religious, delusional, or malevolent.