Interesting with these runaway stars are not a new idea, though of course we haven't had images as spectacular as these. Star formation and its consequences are still little understood.
As for another possible theory on the origins of such stars, not stated in the article, is that they could have been once in a very young trapezia - a specialised type of quadruple multiple star system, (like the Trapezium or theta 1 orionis in the very heart of the Orion Nebula). Here one was then ejected from the tussle for gravitational dominance. This creates a "runaway" star travelling at several hundred kilometres per second, leaving behind a stable triple star - like a common closer binary star with a fainter and/or smaller but more distant companion. I.e Something like Alpha Centauri binary and the more distant Proxima Centauri. This astronomical theory has the bonus of happening near a star formation region, and the improved possibility of interstellar material to interact with.
As I also said elsewhere on another forum;
"Don't wish to be rude, but goodness they look like exactly like some kind of swimming cosmic galactic spermatozoa!"
"Don't shoot me, I'm only the astronomer"
