This is a very shallow understanding of it. The reason why U.S> presidents didn't come to the table was because no concessions were made and there's no reason to legitimize them and their propaganda efforts or appease them with stopping drills (which is not an on/off switch and interferes massively with allocated resources, months of planning and personnel movements) until such time as an effort is made. Trump didn't understand this and told the world at large the nuclear problem was solved, he loves Kim, made a coin where they are on equal footing symbolically, interfered with drills... only to be made a fool, with increased nuclear activity at other sites.

As for these two countries meeting, it is not a result of the Trump's coins, more so a result of growing pressures within NK to do so and from China. Do keep in mind they have frequently made attempts at such measures, but since NK's demands are essentially "reunification under one Korea with NK at the helm" it rarely amounts to much beyond both Koreas competing together in Olympic events.