The Eyes of Faith
The only conclusion is that the Ascension was only seen by a chosen few. So, do you think the second coming will only be seen by a chosen few?
This Jesus who has been taken up from you into heaven will return in the same way as you have seen him going into heaven.
The "chosen few" must be believers. Those who see through the eyes of faith. That's the only thing that makes sense.
When Jesus comes again, only those who see through the eyes of faith will recognize him. Is that what you conclude, also?