I've heard that before...
Funny, I seem to remember people saying this sort of thing 20 years ago.
Extraterrestrial life - almost certainly, sooner or later, although to pin it down within 20 years is a bit of a stretch. We'll be doing well to have retrieved samples from Mars in that time frame, let alone explored Europa or Titan or Enceladus or any of the other moons that also might harbour life.
Extraterrestrial intelligence - now that's a big ask. Especially if we expect that intelligence to be broadcasting radio waves. When you consider that only once in 4 billion years has Earth itself produced life capable of this, said life has only been able to broadcast radio for the past 100 years at most, and with the way technology is going, we'll have no need for powerful broadcast radio within the next 100 years. Low-powered wifi links acting as relays seems to be the way we are going in this area, and if this becomes the norm the radio shouts from Earth will soon drop to a whisper - one that is unlikely to be detectable from light-years away even with the most sensitive equipment. So the window of time in which such technology may be in widespread use is likely to be vanishingly small.
Furthermore, the environmental conditions required to produce intelligence are incredibly specific. Anyone who has seen or read Jared Diamond's excellent documentary series Guns, Germs and Steel will realise how specific the combination of geography, climate, ecology, and sociology have to be in order for advanced civilisation and technology to emerge. When you consider the specificity of those conditions, and the resulting tiny time window in the vast sweep of this planet's history, it is easy to see that while life in the universe is probably commonplace, intelligence almost certainly is not.
Even though there are potentially dozens of billions of life-bearing planets in our galaxy alone, which does improve the odds for there being intelligent civilisations at some stage of evolution, the chances are that such civilisations are spread so far apart that by the time the signals from one reach the antennae of another, the sender will have long since ceased to exist, or will have changed beyond anything the receiver might recognise as intelligence.
That's not to say we should stop searching, by any means. But we do need to face the realities of such a search, and citing time frames of 20 years, every 20 years or so, isn't being realistic about it.