> a handful of remotely meaningful repos

If there's a trend to leave a platform it won't start with the most entrenched users (largest repos).

They acknowledge your concern in the article and their analysis does apply to those few who are leaving. But to be fair the title can be interpreted either way and the most reasonable read for anyone is "some of them are leaving". I'd find it clickbaity if they said "why developers are leaving en-masse" and then point out to the regular turnover. There's clearly a trend, what's not clear is if it gains momentum.