Wait, if we would see the supernova of Betelgeuse in tomorrow's sky it actually exploded before Copernicus, Kepler and Newton were even born and while England and France fought the longest series of conflicts in known history?
So we're actually not searching for exoplanets, but for exoplanets that were at this place a few decades or centuries ago.
Given that mankind advanced from hunters and gatherers to guys sitting infront of machines and typing texts about spaceflight and astronomy into these machines while the texts get sent around the globe in less than a second it seems more and more unlikely to me that there will be aliens, who might have been hunters and gatherers a few millennia back, interested into this specific section of space in exactly this century.
I just destroyed any sci-fi stories for me in less than 15 minutes...