This newspaper has a hard on for downplaying north Korean aggression.

Such a fucking chickenhawk you are. "Aw, these authors want to BUST MASSIVE LOADS all over KOREAN STRONGMEN. They want to be TOPPED by KIM JONG UN!" literally just because they want the peaceful reunification of their nation instead of a war for the US to have effective control of a land border with China.

This author makes every possible attempt to downplay North Korean aggression, blaming it on SK or the US every time.

From what you share I see quoting activists and trying to defuse stories that seem very improbable because there is a long history of SK and US media just making shit up about NK and it being gobbled up uncritically. But please, tell me about unicorns and state-mandated haircuts, it'll be a good use of both our time. The kids eat the rats and the rats eat the kids.

Edit: Oh, but to answer the main question I missed:

It’s gotten to the point where Korean intelligence officials are telling reporters to hold off on relaying reports about North Korean troops from Ukrainian officials until they receive third-party confirmation

Because it's talking about intelligence officials talking directly to reporters, my feeling is that it's an anonymous source, though it should definitely have made this clear.