Earlier quoted context omitted.
Sure, it's a generalization, not an absolute. But for me there's not a big difference between "I'm the end product" and "I'm an intermediate product used to increase sales of the end product". Microsoft isn't a charity; they're an oligopoly pushing hard to keep their stock price up.
I think your characterization of being an "intermediate product" is also dubious since you aren't being sold in any reasonable sense ala the way you are with ad tech. And whilst MS are obviously in the business of making money that doesn't mean it's the only thing they'll do.
We can't know whether I'm an intermediate product without knowing their goals, which they're unlikely to be transparent about. But lets suppose one of their goals is usage and market share statistics that they use as proof to convince paying customers. In that case, my usage is very much an intermediate product.
Or let's imagine that one of their goals is restored market dominance in developer tools. To that end, they would like their competitors to receive less money, leading to their collapse. If they paid somebody else to give away developer tools for that purpose, I'd obviously be the product. That they're paying for that internally obscures it, but fundamentally doesn't change the exploitative nature of the relationship.