This is a pretty article, but wildly silly.

Our technological society will be long gone by the point we'd be able to move asteroids around, unless we prevent the immediate triple threat of the climate disaster, the destruction of the biosphere, and resource exhaustion.

And it seems almost certain we aren't going to deal with that. We should have started 40 years ago, and yet we are still in the "promising to fix things later" phase.

I'm fairly sure that these aliens you postulate don't exist, for exactly the same reason - Fermi's Great Filter. If by some amazing piece of luck they exist, all they have to do to see if we are technologically sophisticated is wait a century and see if our society still exists.

As a footnote, I'm appalled at how many people seem to think that asteroid strikes and similar astronomical phenomena should be our top priority. Such events occur on average tens of millions of years apart. But we are seeing the effects of the climate catastrophe today, right now.

This is very much like refusing to leave a burning building because you're planning your great-grandchildren's retirement fund.