There's a lot of research into some of these ideas at the moment. The terms they use aren't necessarily the same but many similar ideas. I think for the most part, the evidence in support of many of them is fairly weak but at the same time many of these ideas are much harder to test well than it might seem at first. I give a certain amount of pass to people trying to test them because in this area, trying to pin down something often is a bit like trying to study an individual cloud: you can kind of see it there, but if you were to try to measure its boundaries and dynamics, it would be harder to do than it might seem at first glance, and you'd end up more easily making very general observations about it than you might like.
One thought I had when reading it is that people's environments are much more stable than is usually recognized. The piece acknowledges this somewhat, but I think it's more of an issue than most like to admit. Even when someone tries to change it, it can be difficult, because assets and SES can be difficult to change, other people resist it due to their own incentives like the essay points out, and even when other people don't really care much they often will resist it unintentionally due to schemas about personality change and so forth. "Once an X, always an X" regardless of whether you're talking about vocation, career, social characteristics, whatever — even though that statement isn't actually true beyond some kind of general sense of it. Or they just are used to seeing someone in a particular setting and so don't see them in another.
Another issue that's maybe murkier is the essay is a bit loose about person characteristics, even at a given point in time, versus situation characteristics. I don't know that it affects the arguments very much at all, the points still stand, but it sometimes drifts into talking about "personality" when I think it really means something more relational, like "role" or "interactional pattern" or something like that.