It'll still happen, China was putting YUGE pressure on NK not to attend. Trump cancelled the meeting & removed Chinese leverage & in the letter claims it'll be good for both the USA & NK. Trump even used NK language in the cancellation letter. Kim shut down his testing site, something's going on that I wouldn't take at face value that I don't think the media will figure out.
At any rate, I guess it comes down to whether or not you think Trump knows what he's doing. For some particular reason Iranian assets are getting wiped out in Syria at record rates, I think the guy knows what he's doing