There are three ways the plague manifests: bubonic (Black Death, highly treatable), pneumonic [1] (what this researcher died of) and septicemic (gets in your blood–super nasty, but also doesn't spread easily).

Pneumonic is the most transmissible. There are also no commercially-available vaccines for it in most countries. That's why this is worth paying attention to. Not reacting. But keeping a close eye on. Russia being Russia we'll probably only learn if containment was lost from Mongolia or China.

[1] https://en.wikipedia.org/wiki/Pneumonic_plague