Cosmic Horror

In a sense, yes and no. It's far easier to pick out some very irregular signal (human communication) in a sea of noise (all the spectra coming from every planet orbiting a star) than to randomly recognise that a specific planet has a specific atmospheric composition. At the same time: To pick out that signal, they have to be scanning the part of their sky where the earth is.

To put it this way: Any advanced civilisation that takes a closer look at our specific planet (as we're doing every day with loads of planets) and looks at the absorption spectrum of our atmosphere (like we do) would recognise that there's a high probability of life on our planet. Maybe they could even infer a high probability of "intelligent" life (broadly speaking). On the other hand, any civilisation that looks in our general direction would likely be quick to notice that there's some non-random signal coming from around where we are, and may decide to check it out more closely, eventually homing in on our planet. At that point, they'll likely be quite certain (together with the evidence from our atmosphere) that there is intelligent life on our planet.

Either way, I like the following way of looking at things: The universe is estimated to be around 13 billion years old. The Earth is estimated to be around 6 billion (please arrest me if I'm wrong here, I'm talking off the top of my head). For the first couple billion years, no planets, or at least planets with relatively diverse elemental composition, existed. I see it as not entirely unlikely that we're quite early in developing a space-faring society in the universal sense. There's not that many solar systems with the composition needed to sustain life as we know it that came into existence before ours, so we might just be first.

If that's the case, we might be the civilisation that others are warning each other about in a couple million years.