Yes, it could be diverted. To where depends on what the weather is like at alternate airports and a whole host of other factors.

I was once diverted from IAH to HOU, where we sat on the tarmac for 2+ hours, and missed a connection to BOG. They wouldn't let us off the plane.

I don't know that HOU is an option for a 787 coming from SCL. I imagine DFW or AUS would be the most likely next options.

But I think you're getting ahead of yourself. I think it's pretty rare for the airport to close completely and I imagine a long international flight like yours has high priority for landing.

If you do get diverted, just pull out your phone as soon as you can and start looking for alternatives, but there are so many possible contingencies, I don't think it's worth worrying about now.