Most journos have a process, which usually involves telling potential whistleblowers to use an encrypted contact method.

But that doesn't stop people contacting them on unencrypted mediums like tiktok.

What tiktok would have been looking for would be a conversation like this one:

Whistleblower - "I have information on xyz"

Reporter - "Not safe to talk on over social media like this, contact me on [insert encrypted messaging app] and we can talk further"

Unless the reporter was an idiot, which is less likely but also possible.