It’s still a matter of timescale, as in “how far future are we talking?”. On a stellar scale, they’d need to get here in the next billion years or so before the expansion of the sun boils off everything above the lithosphere. On a geological scale, it’s only a couple hundred million years 'til everything that isn’t already buried or washed into the sea is getting squashed into a new pangea. On a climatological scale, corrosion and decay/overgrowth will render almost all artifacts unrecognizable within a couple of thousand years, though it’d be a few tens of thousands before our impact on the atmosphere is nulled. On a human timescale, the inverse-square law means that our radio signals are only detectable without astronomically-sized antennas within a shell of a few dozen light years or so.