This 'official' account gives the impression that no term had much common currency, apart from the jokey 'super-hardcore do-gooder' before the end of 2011. I can't comment about whether other branches of the community used terms in a similar way- I've never heard of felicifia. http://www.effective-altruism.com/the-history-of-the-term-effective-altruism/
I'm not sure that it's the corporate structure that makes negative selection more useful in the data entry case. It's not the fact that the data-entry clerk is part of a large organisation that means that a slightly incompetent data-entry clerk is more disruptive than a genius-level one is helpful. Rather it's the fact that data-entry is a relatively low skill job and with relatively little room for excelling above mere competence. Leaving the corporation wholly out of it, and imagining a person doing data entry in complete isolation, the most helpful data-entry clerk would still be selected by making sure they weren't terrible, but weren't necessarily brilliant, at typing and remaining attentive etc. I think this idea is supported by the fact that for higher level/skill positions, one probably would want to employ more positive selection.
If your point was specifically that insubordination (and not just slight incompetence in general) is more harmful than genius-level work is helpful, then I guess that, in an obvious sense, the harm of insubordination is due to the corporate nature of work (since you can't be insubordinate outside of a group hierarchy). But then I'm not sure that insubordination-worries requires negative selection, or at least not a wide range of negative selection tests. Sure, you might want to include a negative selection test along the lines of 'are they likely to do the opposite of what they're told on a whim occasionally?', but it's an open question whether the rest of your criteria would be negative or positive.
I certainly agree that effective altruism existed long before GWWC.
The discussion I'm addressing though is about the origin of the term "effective altruist."