You are correct that we wouldn't know what is there, or even if the star is still active.

However, from a practical standpoint, we wouldn't bother heading straight to a destination 25000 ly away, even at 1000 times C. There's plenty of real estate closer by that we'd colonize first, then use those as staging points for the next closest stars, etc.

There would have to be some event (intelligent signals, artificial dimming of the star, or something else extraordinary) that would cause us to skip over everything in the middle.