I think Hugo may be correct in the idea that there is some type of option on the table for a staged alien 'threat' in the future, but I don't see this as a likely scenario in the next 50+ years.
I do think without a doubt that other life exists, they observe and even visit this planet, but it has been well noted in the past that the suggestion of "aliens" was promoted to cover up military projects witnessed by the public, especially the desert regions where these projects were likely based.
It's quite possible that they are pre-emptively suggesting the notion of "aliens exist" to cover up for advanced projects that they have in the works that may be seen by the public, like which happened decades ago.
The idea that aliens are demons, to me, is insanity. I don't know if that is some attempt to glorify the human race as saints, but it's far from the truth. We're now far from being worthy of judging whether another race is evil or not.