Because these planets are orbiting very small stars, and hence have to be close in to be in the inhabitable zone, they will be tidally locked. So one side of the planet will be impossibly hot for any life, the other side impossibly cold.
We need to detect planets around bigger stars that are similar to our Sun. They won't be tidally locked, and any planet in the habitable zone, and which is the right size, has a faint possibility of being genuinely Earth-like. But we don't have the technology to detect such planets due to the glare of the star. We need more powerful telescopes and better technology.
Another link regarding these planets:
Could TRAPPIST-1 Be Home to a Galactic Alien Empire?
"Shostak says we should look for radio signals that can tell us if there’s possibly intelligent life on these planets".
Even if there is intelligent life, it's highly unlikely they'll have radio. Dolphins don't have radio. Humans only have had radio about 1/1000th of the time we've existed.
I reckon that planets that are genuinely similar to Earth will not be common, perhaps one in a million or perhaps even one in ten million? And perhaps only one in a thousand of them will have evolved a species that uses radio and has an advanced technological civilisation similar to ours. Most would be like Earth without humans.