From the article:
First, job-hopping millennials proved disloyal to employers, and now apparently they’re also disloyal to each other.
I would say, first employers proved disloyal to their employees . . .
The rest is just a rational response to a changing work environment and culture.
News flash: people early in their business careers make different tradeoffs than people late in their careers.
Not untrue, but it's important to note that in many cases 'workplace friend' is basically 'someone they made me sit near that I feel share some interests'. Not exactly someone you'd invite to your birthday party.
The question can be interpreted in many ways. I could think that a friend who is making me choose between them and a promotion is not a friend worth having.
The article implies that Baby Boomers are more virtuous, however I'd contend that those same people wouldn't have been so virtuous when they were 18-24.
Loyalty from the 18-24 age-group is difficult to come by, regardless of which generation they belong to.
Now, the article fails to mention who the subjects of the study were betraying -- their Millennial peers, or non-Millennial ones? I would hazard to guess that most Millennials would happily betray their Boomer co-workers, perhaps even gleefully (schadenfreude?) -- and vice versa.
The question is open to interpretation even more -- Millennials count potentially everybody as a "workplace friend" (due to a far larger pool of competition), whereas Baby Boomers generally have only themselves as workplace friends.