No. Because most people would work it out as one of two possibilities.
1: God is an All Powerful creator and in all the Universe, he certainly did not just create us. So the proof of extraterrestrial life, especially intelligent life capable of what we would recognise as communication would reinforce the idea that God simply created other life besides us.
2: The extraterrestrial would be construed as the Devil and it would reinforce the idea that God wants us to "fight" him.
All you need to do is look at 35,000 years worth of human history to see that people don't just stop believing in something because of new developments.
Time was disease was the will of God. Now we have vaccinations and it's the will of God to give those vaccinations to the less fortunate.
So believe me, the truly religious zealots will find away to work God into the presence of extraterrestrial life somehow.