Should North Korea be allowed to participate in the 2018 Winter Olympics?

So for the new year Kim Jung Un made his New Years address, in which he was propositioning South Korea to allow North Korea to participate in the upcoming 2018 Winter Olympics, as a gesture of hope to “come together as a culture/people” to show their strength United.

While this is a glimmer of hope, he later changed his tone towards the US (maybe rightfully so), saying that NK nuclear power matches the US nuclear power, and the “button” is always on his office desk”. It’s said not to be taken as a threat, but rather reality.

Here’s where to find the article

Would it be wise if SK to allow this? Also, could it potentially be a threat, almost like a “Trojan horse” a guise for an attack?

What are your thoughts?